// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2018 Cadence Design Systems Inc.
 *
 * Author: Boris Brezillon <boris.brezillon@bootlin.com>
 */

#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/i3c/master.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>
#include <linux/of_device.h>

#define DEV_ID                          0x0
#define DEV_ID_I3C_MASTER               0x5034

#define CONF_STATUS0                    0x4
#define CONF_STATUS0_CMDR_DEPTH(x)      (4 << (((x) & GENMASK(31, 29)) >> 29))
#define CONF_STATUS0_ECC_CHK            BIT(28)
#define CONF_STATUS0_INTEG_CHK          BIT(27)
#define CONF_STATUS0_CSR_DAP_CHK        BIT(26)
#define CONF_STATUS0_TRANS_TOUT_CHK     BIT(25)
#define CONF_STATUS0_PROT_FAULTS_CHK    BIT(24)
#define CONF_STATUS0_GPO_NUM(x)         (((x) & GENMASK(23, 16)) >> 16)
#define CONF_STATUS0_GPI_NUM(x)         (((x) & GENMASK(15, 8)) >> 8)
#define CONF_STATUS0_IBIR_DEPTH(x)      (4 << (((x) & GENMASK(7, 6)) >> 7))
#define CONF_STATUS0_SUPPORTS_DDR       BIT(5)
#define CONF_STATUS0_SEC_MASTER         BIT(4)
#define CONF_STATUS0_DEVS_NUM(x)        ((x) & GENMASK(3, 0))

#define CONF_STATUS1                    0x8
#define CONF_STATUS1_IBI_HW_RES(x)      ((((x) & GENMASK(31, 28)) >> 28) + 1)
#define CONF_STATUS1_CMD_DEPTH(x)       (4 << (((x) & GENMASK(27, 26)) >> 26))
#define CONF_STATUS1_SLVDDR_RX_DEPTH(x) (8 << (((x) & GENMASK(25, 21)) >> 21))
#define CONF_STATUS1_SLVDDR_TX_DEPTH(x) (8 << (((x) & GENMASK(20, 16)) >> 16))
#define CONF_STATUS1_IBI_DEPTH(x)       (2 << (((x) & GENMASK(12, 10)) >> 10))
#define CONF_STATUS1_RX_DEPTH(x)        (8 << (((x) & GENMASK(9, 5)) >> 5))
#define CONF_STATUS1_TX_DEPTH(x)        (8 << ((x) & GENMASK(4, 0)))

#define REV_ID                          0xc
#define REV_ID_VID(id)                  (((id) & GENMASK(31, 20)) >> 20)
#define REV_ID_PID(id)                  (((id) & GENMASK(19, 8)) >> 8)
#define REV_ID_REV_MAJOR(id)            (((id) & GENMASK(7, 4)) >> 4)
#define REV_ID_REV_MINOR(id)            ((id) & GENMASK(3, 0))

#define CTRL                            0x10
#define CTRL_DEV_EN                     BIT(31)
#define CTRL_HALT_EN                    BIT(30)
#define CTRL_MCS                        BIT(29)
#define CTRL_MCS_EN                     BIT(28)
#define CTRL_THD_DELAY(x)               (((x) << 24) & GENMASK(25, 24))
#define CTRL_HJ_DISEC                   BIT(8)
#define CTRL_MST_ACK                    BIT(7)
#define CTRL_HJ_ACK                     BIT(6)
#define CTRL_HJ_INIT                    BIT(5)
#define CTRL_MST_INIT                   BIT(4)
#define CTRL_AHDR_OPT                   BIT(3)
#define CTRL_PURE_BUS_MODE              0
#define CTRL_MIXED_FAST_BUS_MODE        2
#define CTRL_MIXED_SLOW_BUS_MODE        3
#define CTRL_BUS_MODE_MASK              GENMASK(1, 0)
#define THD_DELAY_MAX                   3

#define PRESCL_CTRL0                    0x14
#define PRESCL_CTRL0_I2C(x)             ((x) << 16)
#define PRESCL_CTRL0_I3C(x)             (x)
#define PRESCL_CTRL0_MAX                GENMASK(9, 0)

#define PRESCL_CTRL1                    0x18
#define PRESCL_CTRL1_PP_LOW_MASK        GENMASK(15, 8)
#define PRESCL_CTRL1_PP_LOW(x)          ((x) << 8)
#define PRESCL_CTRL1_OD_LOW_MASK        GENMASK(7, 0)
#define PRESCL_CTRL1_OD_LOW(x)          (x)

#define MST_IER                         0x20
#define MST_IDR                         0x24
#define MST_IMR                         0x28
#define MST_ICR                         0x2c
#define MST_ISR                         0x30
#define MST_INT_HALTED                  BIT(18)
#define MST_INT_MR_DONE                 BIT(17)
#define MST_INT_IMM_COMP                BIT(16)
#define MST_INT_TX_THR                  BIT(15)
#define MST_INT_TX_OVF                  BIT(14)
#define MST_INT_IBID_THR                BIT(12)
#define MST_INT_IBID_UNF                BIT(11)
#define MST_INT_IBIR_THR                BIT(10)
#define MST_INT_IBIR_UNF                BIT(9)
#define MST_INT_IBIR_OVF                BIT(8)
#define MST_INT_RX_THR                  BIT(7)
#define MST_INT_RX_UNF                  BIT(6)
#define MST_INT_CMDD_EMP                BIT(5)
#define MST_INT_CMDD_THR                BIT(4)
#define MST_INT_CMDD_OVF                BIT(3)
#define MST_INT_CMDR_THR                BIT(2)
#define MST_INT_CMDR_UNF                BIT(1)
#define MST_INT_CMDR_OVF                BIT(0)

#define MST_STATUS0                     0x34
#define MST_STATUS0_IDLE                BIT(18)
#define MST_STATUS0_HALTED              BIT(17)
#define MST_STATUS0_MASTER_MODE         BIT(16)
#define MST_STATUS0_TX_FULL             BIT(13)
#define MST_STATUS0_IBID_FULL           BIT(12)
#define MST_STATUS0_IBIR_FULL           BIT(11)
#define MST_STATUS0_RX_FULL             BIT(10)
#define MST_STATUS0_CMDD_FULL           BIT(9)
#define MST_STATUS0_CMDR_FULL           BIT(8)
#define MST_STATUS0_TX_EMP              BIT(5)
#define MST_STATUS0_IBID_EMP            BIT(4)
#define MST_STATUS0_IBIR_EMP            BIT(3)
#define MST_STATUS0_RX_EMP              BIT(2)
#define MST_STATUS0_CMDD_EMP            BIT(1)
#define MST_STATUS0_CMDR_EMP            BIT(0)

#define CMDR                            0x38
#define CMDR_NO_ERROR                   0
#define CMDR_DDR_PREAMBLE_ERROR         1
#define CMDR_DDR_PARITY_ERROR           2
#define CMDR_DDR_RX_FIFO_OVF            3
#define CMDR_DDR_TX_FIFO_UNF            4
#define CMDR_M0_ERROR                   5
#define CMDR_M1_ERROR                   6
#define CMDR_M2_ERROR                   7
#define CMDR_MST_ABORT                  8
#define CMDR_NACK_RESP                  9
#define CMDR_INVALID_DA                 10
#define CMDR_DDR_DROPPED                11
#define CMDR_ERROR(x)                   (((x) & GENMASK(27, 24)) >> 24)
#define CMDR_XFER_BYTES(x)              (((x) & GENMASK(19, 8)) >> 8)
#define CMDR_CMDID_HJACK_DISEC          0xfe
#define CMDR_CMDID_HJACK_ENTDAA         0xff
#define CMDR_CMDID(x)                   ((x) & GENMASK(7, 0))

#define IBIR                            0x3c
#define IBIR_ACKED                      BIT(12)
#define IBIR_SLVID(x)                   (((x) & GENMASK(11, 8)) >> 8)
#define IBIR_ERROR                      BIT(7)
#define IBIR_XFER_BYTES(x)              (((x) & GENMASK(6, 2)) >> 2)
#define IBIR_TYPE_IBI                   0
#define IBIR_TYPE_HJ                    1
#define IBIR_TYPE_MR                    2
#define IBIR_TYPE(x)                    ((x) & GENMASK(1, 0))

#define SLV_IER                         0x40
#define SLV_IDR                         0x44
#define SLV_IMR                         0x48
#define SLV_ICR                         0x4c
#define SLV_ISR                         0x50
#define SLV_INT_TM                      BIT(20)
#define SLV_INT_ERROR                   BIT(19)
#define SLV_INT_EVENT_UP                BIT(18)
#define SLV_INT_HJ_DONE                 BIT(17)
#define SLV_INT_MR_DONE                 BIT(16)
#define SLV_INT_DA_UPD                  BIT(15)
#define SLV_INT_SDR_FAIL                BIT(14)
#define SLV_INT_DDR_FAIL                BIT(13)
#define SLV_INT_M_RD_ABORT              BIT(12)
#define SLV_INT_DDR_RX_THR              BIT(11)
#define SLV_INT_DDR_TX_THR              BIT(10)
#define SLV_INT_SDR_RX_THR              BIT(9)
#define SLV_INT_SDR_TX_THR              BIT(8)
#define SLV_INT_DDR_RX_UNF              BIT(7)
#define SLV_INT_DDR_TX_OVF              BIT(6)
#define SLV_INT_SDR_RX_UNF              BIT(5)
#define SLV_INT_SDR_TX_OVF              BIT(4)
#define SLV_INT_DDR_RD_COMP             BIT(3)
#define SLV_INT_DDR_WR_COMP             BIT(2)
#define SLV_INT_SDR_RD_COMP             BIT(1)
#define SLV_INT_SDR_WR_COMP             BIT(0)

#define SLV_STATUS0                     0x54
#define SLV_STATUS0_REG_ADDR(s)         (((s) & GENMASK(23, 16)) >> 16)
#define SLV_STATUS0_XFRD_BYTES(s)       ((s) & GENMASK(15, 0))

#define SLV_STATUS1                     0x58
#define SLV_STATUS1_AS(s)               (((s) & GENMASK(21, 20)) >> 20)
#define SLV_STATUS1_VEN_TM              BIT(19)
#define SLV_STATUS1_HJ_DIS              BIT(18)
#define SLV_STATUS1_MR_DIS              BIT(17)
#define SLV_STATUS1_PROT_ERR            BIT(16)
#define SLV_STATUS1_DA(x)               (((s) & GENMASK(15, 9)) >> 9)
#define SLV_STATUS1_HAS_DA              BIT(8)
#define SLV_STATUS1_DDR_RX_FULL         BIT(7)
#define SLV_STATUS1_DDR_TX_FULL         BIT(6)
#define SLV_STATUS1_DDR_RX_EMPTY        BIT(5)
#define SLV_STATUS1_DDR_TX_EMPTY        BIT(4)
#define SLV_STATUS1_SDR_RX_FULL         BIT(3)
#define SLV_STATUS1_SDR_TX_FULL         BIT(2)
#define SLV_STATUS1_SDR_RX_EMPTY        BIT(1)
#define SLV_STATUS1_SDR_TX_EMPTY        BIT(0)

#define CMD0_FIFO                       0x60
#define CMD0_FIFO_IS_DDR                BIT(31)
#define CMD0_FIFO_IS_CCC                BIT(30)
#define CMD0_FIFO_BCH                   BIT(29)
#define XMIT_BURST_STATIC_SUBADDR       0
#define XMIT_SINGLE_INC_SUBADDR         1
#define XMIT_SINGLE_STATIC_SUBADDR      2
#define XMIT_BURST_WITHOUT_SUBADDR      3
#define CMD0_FIFO_PRIV_XMIT_MODE(m)     ((m) << 27)
#define CMD0_FIFO_SBCA                  BIT(26)
#define CMD0_FIFO_RSBC                  BIT(25)
#define CMD0_FIFO_IS_10B                BIT(24)
#define CMD0_FIFO_PL_LEN(l)             ((l) << 12)
#define CMD0_FIFO_PL_LEN_MAX            4095
#define CMD0_FIFO_DEV_ADDR(a)           ((a) << 1)
#define CMD0_FIFO_RNW                   BIT(0)

#define CMD1_FIFO                       0x64
#define CMD1_FIFO_CMDID(id)             ((id) << 24)
#define CMD1_FIFO_CSRADDR(a)            (a)
#define CMD1_FIFO_CCC(id)               (id)

#define TX_FIFO                         0x68

#define IMD_CMD0                        0x70
#define IMD_CMD0_PL_LEN(l)              ((l) << 12)
#define IMD_CMD0_DEV_ADDR(a)            ((a) << 1)
#define IMD_CMD0_RNW                    BIT(0)

#define IMD_CMD1                        0x74
#define IMD_CMD1_CCC(id)                (id)

#define IMD_DATA                        0x78
#define RX_FIFO                         0x80
#define IBI_DATA_FIFO                   0x84
#define SLV_DDR_TX_FIFO                 0x88
#define SLV_DDR_RX_FIFO                 0x8c

#define CMD_IBI_THR_CTRL                0x90
#define IBIR_THR(t)                     ((t) << 24)
#define CMDR_THR(t)                     ((t) << 16)
#define IBI_THR(t)                      ((t) << 8)
#define CMD_THR(t)                      (t)

#define TX_RX_THR_CTRL                  0x94
#define RX_THR(t)                       ((t) << 16)
#define TX_THR(t)                       (t)

#define SLV_DDR_TX_RX_THR_CTRL          0x98
#define SLV_DDR_RX_THR(t)               ((t) << 16)
#define SLV_DDR_TX_THR(t)               (t)

#define FLUSH_CTRL                      0x9c
#define FLUSH_IBI_RESP                  BIT(23)
#define FLUSH_CMD_RESP                  BIT(22)
#define FLUSH_SLV_DDR_RX_FIFO           BIT(22)
#define FLUSH_SLV_DDR_TX_FIFO           BIT(21)
#define FLUSH_IMM_FIFO                  BIT(20)
#define FLUSH_IBI_FIFO                  BIT(19)
#define FLUSH_RX_FIFO                   BIT(18)
#define FLUSH_TX_FIFO                   BIT(17)
#define FLUSH_CMD_FIFO                  BIT(16)

#define TTO_PRESCL_CTRL0                0xb0
#define TTO_PRESCL_CTRL0_DIVB(x)        ((x) << 16)
#define TTO_PRESCL_CTRL0_DIVA(x)        (x)

#define TTO_PRESCL_CTRL1                0xb4
#define TTO_PRESCL_CTRL1_DIVB(x)        ((x) << 16)
#define TTO_PRESCL_CTRL1_DIVA(x)        (x)

#define DEVS_CTRL                       0xb8
#define DEVS_CTRL_DEV_CLR_SHIFT         16
#define DEVS_CTRL_DEV_CLR_ALL           GENMASK(31, 16)
#define DEVS_CTRL_DEV_CLR(dev)          BIT(16 + (dev))
#define DEVS_CTRL_DEV_ACTIVE(dev)       BIT(dev)
#define DEVS_CTRL_DEVS_ACTIVE_MASK      GENMASK(15, 0)
#define MAX_DEVS                        16

#define DEV_ID_RR0(d)                   (0xc0 + ((d) * 0x10))
#define DEV_ID_RR0_LVR_EXT_ADDR         BIT(11)
#define DEV_ID_RR0_HDR_CAP              BIT(10)
#define DEV_ID_RR0_IS_I3C               BIT(9)
#define DEV_ID_RR0_DEV_ADDR_MASK        (GENMASK(6, 0) | GENMASK(15, 13))
#define DEV_ID_RR0_SET_DEV_ADDR(a)      (((a) & GENMASK(6, 0)) |        \
                                         (((a) & GENMASK(9, 7)) << 6))
#define DEV_ID_RR0_GET_DEV_ADDR(x)      ((((x) >> 1) & GENMASK(6, 0)) | \
                                         (((x) >> 6) & GENMASK(9, 7)))

#define DEV_ID_RR1(d)                   (0xc4 + ((d) * 0x10))
#define DEV_ID_RR1_PID_MSB(pid)         (pid)

#define DEV_ID_RR2(d)                   (0xc8 + ((d) * 0x10))
#define DEV_ID_RR2_PID_LSB(pid)         ((pid) << 16)
#define DEV_ID_RR2_BCR(bcr)             ((bcr) << 8)
#define DEV_ID_RR2_DCR(dcr)             (dcr)
#define DEV_ID_RR2_LVR(lvr)             (lvr)

#define SIR_MAP(x)                      (0x180 + ((x) * 4))
#define SIR_MAP_DEV_REG(d)              SIR_MAP((d) / 2)
#define SIR_MAP_DEV_SHIFT(d, fs)        ((fs) + (((d) % 2) ? 16 : 0))
#define SIR_MAP_DEV_CONF_MASK(d)        (GENMASK(15, 0) << (((d) % 2) ? 16 : 0))
#define SIR_MAP_DEV_CONF(d, c)          ((c) << (((d) % 2) ? 16 : 0))
#define DEV_ROLE_SLAVE                  0
#define DEV_ROLE_MASTER                 1
#define SIR_MAP_DEV_ROLE(role)          ((role) << 14)
#define SIR_MAP_DEV_SLOW                BIT(13)
#define SIR_MAP_DEV_PL(l)               ((l) << 8)
#define SIR_MAP_PL_MAX                  GENMASK(4, 0)
#define SIR_MAP_DEV_DA(a)               ((a) << 1)
#define SIR_MAP_DEV_ACK                 BIT(0)

#define GPIR_WORD(x)                    (0x200 + ((x) * 4))
#define GPI_REG(val, id)                \
        (((val) >> (((id) % 4) * 8)) & GENMASK(7, 0))

#define GPOR_WORD(x)                    (0x220 + ((x) * 4))
#define GPO_REG(val, id)                \
        (((val) >> (((id) % 4) * 8)) & GENMASK(7, 0))

#define ASF_INT_STATUS                  0x300
#define ASF_INT_RAW_STATUS              0x304
#define ASF_INT_MASK                    0x308
#define ASF_INT_TEST                    0x30c
#define ASF_INT_FATAL_SELECT            0x310
#define ASF_INTEGRITY_ERR               BIT(6)
#define ASF_PROTOCOL_ERR                BIT(5)
#define ASF_TRANS_TIMEOUT_ERR           BIT(4)
#define ASF_CSR_ERR                     BIT(3)
#define ASF_DAP_ERR                     BIT(2)
#define ASF_SRAM_UNCORR_ERR             BIT(1)
#define ASF_SRAM_CORR_ERR               BIT(0)

#define ASF_SRAM_CORR_FAULT_STATUS      0x320
#define ASF_SRAM_UNCORR_FAULT_STATUS    0x324
#define ASF_SRAM_CORR_FAULT_INSTANCE(x) ((x) >> 24)
#define ASF_SRAM_CORR_FAULT_ADDR(x)     ((x) & GENMASK(23, 0))

#define ASF_SRAM_FAULT_STATS            0x328
#define ASF_SRAM_FAULT_UNCORR_STATS(x)  ((x) >> 16)
#define ASF_SRAM_FAULT_CORR_STATS(x)    ((x) & GENMASK(15, 0))

#define ASF_TRANS_TOUT_CTRL             0x330
#define ASF_TRANS_TOUT_EN               BIT(31)
#define ASF_TRANS_TOUT_VAL(x)   (x)

#define ASF_TRANS_TOUT_FAULT_MASK       0x334
#define ASF_TRANS_TOUT_FAULT_STATUS     0x338
#define ASF_TRANS_TOUT_FAULT_APB        BIT(3)
#define ASF_TRANS_TOUT_FAULT_SCL_LOW    BIT(2)
#define ASF_TRANS_TOUT_FAULT_SCL_HIGH   BIT(1)
#define ASF_TRANS_TOUT_FAULT_FSCL_HIGH  BIT(0)

#define ASF_PROTO_FAULT_MASK            0x340
#define ASF_PROTO_FAULT_STATUS          0x344
#define ASF_PROTO_FAULT_SLVSDR_RD_ABORT BIT(31)
#define ASF_PROTO_FAULT_SLVDDR_FAIL     BIT(30)
#define ASF_PROTO_FAULT_S(x)            BIT(16 + (x))
#define ASF_PROTO_FAULT_MSTSDR_RD_ABORT BIT(15)
#define ASF_PROTO_FAULT_MSTDDR_FAIL     BIT(14)
#define ASF_PROTO_FAULT_M(x)            BIT(x)

struct cdns_i3c_master_caps {
        u32 cmdfifodepth;
        u32 cmdrfifodepth;
        u32 txfifodepth;
        u32 rxfifodepth;
        u32 ibirfifodepth;
};

struct cdns_i3c_cmd {
        u32 cmd0;
        u32 cmd1;
        u32 tx_len;
        const void *tx_buf;
        u32 rx_len;
        void *rx_buf;
        u32 error;
};

struct cdns_i3c_xfer {
        struct list_head node;
        struct completion comp;
        int ret;
        unsigned int ncmds;
        struct cdns_i3c_cmd cmds[];
};

struct cdns_i3c_data {
        u8 thd_delay_ns;
};

struct cdns_i3c_master {
        struct work_struct hj_work;
        struct i3c_master_controller base;
        u32 free_rr_slots;
        unsigned int maxdevs;
        struct {
                unsigned int num_slots;
                struct i3c_dev_desc **slots;
                spinlock_t lock;
        } ibi;
        struct {
                struct list_head list;
                struct cdns_i3c_xfer *cur;
                spinlock_t lock;
        } xferqueue;
        void __iomem *regs;
        struct clk *sysclk;
        struct clk *pclk;
        struct cdns_i3c_master_caps caps;
        unsigned long i3c_scl_lim;
        const struct cdns_i3c_data *devdata;
};

static inline struct cdns_i3c_master *
to_cdns_i3c_master(struct i3c_master_controller *master)
{
        return container_of(master, struct cdns_i3c_master, base);
}

static void cdns_i3c_master_wr_to_tx_fifo(struct cdns_i3c_master *master,
                                          const u8 *bytes, int nbytes)
{
        writesl(master->regs + TX_FIFO, bytes, nbytes / 4);
        if (nbytes & 3) {
                u32 tmp = 0;

                memcpy(&tmp, bytes + (nbytes & ~3), nbytes & 3);
                writesl(master->regs + TX_FIFO, &tmp, 1);
        }
}

static void cdns_i3c_master_rd_from_rx_fifo(struct cdns_i3c_master *master,
                                            u8 *bytes, int nbytes)
{
        readsl(master->regs + RX_FIFO, bytes, nbytes / 4);
        if (nbytes & 3) {
                u32 tmp;

                readsl(master->regs + RX_FIFO, &tmp, 1);
                memcpy(bytes + (nbytes & ~3), &tmp, nbytes & 3);
        }
}

static bool cdns_i3c_master_supports_ccc_cmd(struct i3c_master_controller *m,
                                             const struct i3c_ccc_cmd *cmd)
{
        if (cmd->ndests > 1)
                return false;

        switch (cmd->id) {
        case I3C_CCC_ENEC(true):
        case I3C_CCC_ENEC(false):
        case I3C_CCC_DISEC(true):
        case I3C_CCC_DISEC(false):
        case I3C_CCC_ENTAS(0, true):
        case I3C_CCC_ENTAS(0, false):
        case I3C_CCC_RSTDAA(true):
        case I3C_CCC_RSTDAA(false):
        case I3C_CCC_ENTDAA:
        case I3C_CCC_SETMWL(true):
        case I3C_CCC_SETMWL(false):
        case I3C_CCC_SETMRL(true):
        case I3C_CCC_SETMRL(false):
        case I3C_CCC_DEFSLVS:
        case I3C_CCC_ENTHDR(0):
        case I3C_CCC_SETDASA:
        case I3C_CCC_SETNEWDA:
        case I3C_CCC_GETMWL:
        case I3C_CCC_GETMRL:
        case I3C_CCC_GETPID:
        case I3C_CCC_GETBCR:
        case I3C_CCC_GETDCR:
        case I3C_CCC_GETSTATUS:
        case I3C_CCC_GETACCMST:
        case I3C_CCC_GETMXDS:
        case I3C_CCC_GETHDRCAP:
                return true;
        default:
                break;
        }

        return false;
}

static int cdns_i3c_master_disable(struct cdns_i3c_master *master)
{
        u32 status;

        writel(readl(master->regs + CTRL) & ~CTRL_DEV_EN, master->regs + CTRL);

        return readl_poll_timeout(master->regs + MST_STATUS0, status,
                                  status & MST_STATUS0_IDLE, 10, 1000000);
}

static void cdns_i3c_master_enable(struct cdns_i3c_master *master)
{
        writel(readl(master->regs + CTRL) | CTRL_DEV_EN, master->regs + CTRL);
}

static struct cdns_i3c_xfer *
cdns_i3c_master_alloc_xfer(struct cdns_i3c_master *master, unsigned int ncmds)
{
        struct cdns_i3c_xfer *xfer;

        xfer = kzalloc(struct_size(xfer, cmds, ncmds), GFP_KERNEL);
        if (!xfer)
                return NULL;

        INIT_LIST_HEAD(&xfer->node);
        xfer->ncmds = ncmds;
        xfer->ret = -ETIMEDOUT;

        return xfer;
}

static void cdns_i3c_master_free_xfer(struct cdns_i3c_xfer *xfer)
{
        kfree(xfer);
}

static void cdns_i3c_master_start_xfer_locked(struct cdns_i3c_master *master)
{
        struct cdns_i3c_xfer *xfer = master->xferqueue.cur;
        unsigned int i;

        if (!xfer)
                return;

        writel(MST_INT_CMDD_EMP, master->regs + MST_ICR);
        for (i = 0; i < xfer->ncmds; i++) {
                struct cdns_i3c_cmd *cmd = &xfer->cmds[i];

                cdns_i3c_master_wr_to_tx_fifo(master, cmd->tx_buf,
                                              cmd->tx_len);
        }

        for (i = 0; i < xfer->ncmds; i++) {
                struct cdns_i3c_cmd *cmd = &xfer->cmds[i];

                writel(cmd->cmd1 | CMD1_FIFO_CMDID(i),
                       master->regs + CMD1_FIFO);
                writel(cmd->cmd0, master->regs + CMD0_FIFO);
        }

        writel(readl(master->regs + CTRL) | CTRL_MCS,
               master->regs + CTRL);
        writel(MST_INT_CMDD_EMP, master->regs + MST_IER);
}

static void cdns_i3c_master_end_xfer_locked(struct cdns_i3c_master *master,
                                            u32 isr)
{
        struct cdns_i3c_xfer *xfer = master->xferqueue.cur;
        int i, ret = 0;
        u32 status0;

        if (!xfer)
                return;

        if (!(isr & MST_INT_CMDD_EMP))
                return;

        writel(MST_INT_CMDD_EMP, master->regs + MST_IDR);

        for (status0 = readl(master->regs + MST_STATUS0);
             !(status0 & MST_STATUS0_CMDR_EMP);
             status0 = readl(master->regs + MST_STATUS0)) {
                struct cdns_i3c_cmd *cmd;
                u32 cmdr, rx_len, id;

                cmdr = readl(master->regs + CMDR);
                id = CMDR_CMDID(cmdr);
                if (id == CMDR_CMDID_HJACK_DISEC ||
                    id == CMDR_CMDID_HJACK_ENTDAA ||
                    WARN_ON(id >= xfer->ncmds))
                        continue;

                cmd = &xfer->cmds[CMDR_CMDID(cmdr)];
                rx_len = min_t(u32, CMDR_XFER_BYTES(cmdr), cmd->rx_len);
                cdns_i3c_master_rd_from_rx_fifo(master, cmd->rx_buf, rx_len);
                cmd->error = CMDR_ERROR(cmdr);
        }

        for (i = 0; i < xfer->ncmds; i++) {
                switch (xfer->cmds[i].error) {
                case CMDR_NO_ERROR:
                        break;

                case CMDR_DDR_PREAMBLE_ERROR:
                case CMDR_DDR_PARITY_ERROR:
                case CMDR_M0_ERROR:
                case CMDR_M1_ERROR:
                case CMDR_M2_ERROR:
                case CMDR_MST_ABORT:
                case CMDR_NACK_RESP:
                case CMDR_DDR_DROPPED:
                        ret = -EIO;
                        break;

                case CMDR_DDR_RX_FIFO_OVF:
                case CMDR_DDR_TX_FIFO_UNF:
                        ret = -ENOSPC;
                        break;

                case CMDR_INVALID_DA:
                default:
                        ret = -EINVAL;
                        break;
                }
        }

        xfer->ret = ret;
        complete(&xfer->comp);

        xfer = list_first_entry_or_null(&master->xferqueue.list,
                                        struct cdns_i3c_xfer, node);
        if (xfer)
                list_del_init(&xfer->node);

        master->xferqueue.cur = xfer;
        cdns_i3c_master_start_xfer_locked(master);
}

static void cdns_i3c_master_queue_xfer(struct cdns_i3c_master *master,
                                       struct cdns_i3c_xfer *xfer)
{
        unsigned long flags;

        init_completion(&xfer->comp);
        spin_lock_irqsave(&master->xferqueue.lock, flags);
        if (master->xferqueue.cur) {
                list_add_tail(&xfer->node, &master->xferqueue.list);
        } else {
                master->xferqueue.cur = xfer;
                cdns_i3c_master_start_xfer_locked(master);
        }
        spin_unlock_irqrestore(&master->xferqueue.lock, flags);
}

static void cdns_i3c_master_unqueue_xfer(struct cdns_i3c_master *master,
                                         struct cdns_i3c_xfer *xfer)
{
        unsigned long flags;

        spin_lock_irqsave(&master->xferqueue.lock, flags);
        if (master->xferqueue.cur == xfer) {
                u32 status;

                writel(readl(master->regs + CTRL) & ~CTRL_DEV_EN,
                       master->regs + CTRL);
                readl_poll_timeout_atomic(master->regs + MST_STATUS0, status,
                                          status & MST_STATUS0_IDLE, 10,
                                          1000000);
                master->xferqueue.cur = NULL;
                writel(FLUSH_RX_FIFO | FLUSH_TX_FIFO | FLUSH_CMD_FIFO |
                       FLUSH_CMD_RESP,
                       master->regs + FLUSH_CTRL);
                writel(MST_INT_CMDD_EMP, master->regs + MST_IDR);
                writel(readl(master->regs + CTRL) | CTRL_DEV_EN,
                       master->regs + CTRL);
        } else {
                list_del_init(&xfer->node);
        }
        spin_unlock_irqrestore(&master->xferqueue.lock, flags);
}

static enum i3c_error_code cdns_i3c_cmd_get_err(struct cdns_i3c_cmd *cmd)
{
        switch (cmd->error) {
        case CMDR_M0_ERROR:
                return I3C_ERROR_M0;

        case CMDR_M1_ERROR:
                return I3C_ERROR_M1;

        case CMDR_M2_ERROR:
        case CMDR_NACK_RESP:
                return I3C_ERROR_M2;

        default:
                break;
        }

        return I3C_ERROR_UNKNOWN;
}

static int cdns_i3c_master_send_ccc_cmd(struct i3c_master_controller *m,
                                        struct i3c_ccc_cmd *cmd)
{
        struct cdns_i3c_master *master = to_cdns_i3c_master(m);
        struct cdns_i3c_xfer *xfer;
        struct cdns_i3c_cmd *ccmd;
        int ret;

        xfer = cdns_i3c_master_alloc_xfer(master, 1);
        if (!xfer)
                return -ENOMEM;

        ccmd = xfer->cmds;
        ccmd->cmd1 = CMD1_FIFO_CCC(cmd->id);
        ccmd->cmd0 = CMD0_FIFO_IS_CCC |
                     CMD0_FIFO_PL_LEN(cmd->dests[0].payload.len);

        if (cmd->id & I3C_CCC_DIRECT)
                ccmd->cmd0 |= CMD0_FIFO_DEV_ADDR(cmd->dests[0].addr);

        if (cmd->rnw) {
                ccmd->cmd0 |= CMD0_FIFO_RNW;
                ccmd->rx_buf = cmd->dests[0].payload.data;
                ccmd->rx_len = cmd->dests[0].payload.len;
        } else {
                ccmd->tx_buf = cmd->dests[0].payload.data;
                ccmd->tx_len = cmd->dests[0].payload.len;
        }

        cdns_i3c_master_queue_xfer(master, xfer);
        if (!wait_for_completion_timeout(&xfer->comp, msecs_to_jiffies(1000)))
                cdns_i3c_master_unqueue_xfer(master, xfer);

        ret = xfer->ret;
        cmd->err = cdns_i3c_cmd_get_err(&xfer->cmds[0]);
        cdns_i3c_master_free_xfer(xfer);

        return ret;
}

static int cdns_i3c_master_priv_xfers(struct i3c_dev_desc *dev,
                                      struct i3c_priv_xfer *xfers,
                                      int nxfers)
{
        struct i3c_master_controller *m = i3c_dev_get_master(dev);
        struct cdns_i3c_master *master = to_cdns_i3c_master(m);
        int txslots = 0, rxslots = 0, i, ret;
        struct cdns_i3c_xfer *cdns_xfer;

        for (i = 0; i < nxfers; i++) {
                if (xfers[i].len > CMD0_FIFO_PL_LEN_MAX)
                        return -ENOTSUPP;
        }

        if (!nxfers)
                return 0;

        if (nxfers > master->caps.cmdfifodepth ||
            nxfers > master->caps.cmdrfifodepth)
                return -ENOTSUPP;

        /*
         * First make sure that all transactions (block of transfers separated
         * by a STOP marker) fit in the FIFOs.
         */
        for (i = 0; i < nxfers; i++) {
                if (xfers[i].rnw)
                        rxslots += DIV_ROUND_UP(xfers[i].len, 4);
                else
                        txslots += DIV_ROUND_UP(xfers[i].len, 4);
        }

        if (rxslots > master->caps.rxfifodepth ||
            txslots > master->caps.txfifodepth)
                return -ENOTSUPP;

        cdns_xfer = cdns_i3c_master_alloc_xfer(master, nxfers);
        if (!cdns_xfer)
                return -ENOMEM;

        for (i = 0; i < nxfers; i++) {
                struct cdns_i3c_cmd *ccmd = &cdns_xfer->cmds[i];
                u32 pl_len = xfers[i].len;

                ccmd->cmd0 = CMD0_FIFO_DEV_ADDR(dev->info.dyn_addr) |
                        CMD0_FIFO_PRIV_XMIT_MODE(XMIT_BURST_WITHOUT_SUBADDR);

                if (xfers[i].rnw) {
                        ccmd->cmd0 |= CMD0_FIFO_RNW;
                        ccmd->rx_buf = xfers[i].data.in;
                        ccmd->rx_len = xfers[i].len;
                        pl_len++;
                } else {
                        ccmd->tx_buf = xfers[i].data.out;
                        ccmd->tx_len = xfers[i].len;
                }

                ccmd->cmd0 |= CMD0_FIFO_PL_LEN(pl_len);

                if (i < nxfers - 1)
                        ccmd->cmd0 |= CMD0_FIFO_RSBC;

                if (!i)
                        ccmd->cmd0 |= CMD0_FIFO_BCH;
        }

        cdns_i3c_master_queue_xfer(master, cdns_xfer);
        if (!wait_for_completion_timeout(&cdns_xfer->comp,
                                         msecs_to_jiffies(1000)))
                cdns_i3c_master_unqueue_xfer(master, cdns_xfer);

        ret = cdns_xfer->ret;

        for (i = 0; i < nxfers; i++)
                xfers[i].err = cdns_i3c_cmd_get_err(&cdns_xfer->cmds[i]);

        cdns_i3c_master_free_xfer(cdns_xfer);

        return ret;
}

static int cdns_i3c_master_i2c_xfers(struct i2c_dev_desc *dev,
                                     const struct i2c_msg *xfers, int nxfers)
{
        struct i3c_master_controller *m = i2c_dev_get_master(dev);
        struct cdns_i3c_master *master = to_cdns_i3c_master(m);
        unsigned int nrxwords = 0, ntxwords = 0;
        struct cdns_i3c_xfer *xfer;
        int i, ret = 0;

        if (nxfers > master->caps.cmdfifodepth)
                return -ENOTSUPP;

        for (i = 0; i < nxfers; i++) {
                if (xfers[i].len > CMD0_FIFO_PL_LEN_MAX)
                        return -ENOTSUPP;

                if (xfers[i].flags & I2C_M_RD)
                        nrxwords += DIV_ROUND_UP(xfers[i].len, 4);
                else
                        ntxwords += DIV_ROUND_UP(xfers[i].len, 4);
        }

        if (ntxwords > master->caps.txfifodepth ||
            nrxwords > master->caps.rxfifodepth)
                return -ENOTSUPP;

        xfer = cdns_i3c_master_alloc_xfer(master, nxfers);
        if (!xfer)
                return -ENOMEM;

        for (i = 0; i < nxfers; i++) {
                struct cdns_i3c_cmd *ccmd = &xfer->cmds[i];

                ccmd->cmd0 = CMD0_FIFO_DEV_ADDR(xfers[i].addr) |
                        CMD0_FIFO_PL_LEN(xfers[i].len) |
                        CMD0_FIFO_PRIV_XMIT_MODE(XMIT_BURST_WITHOUT_SUBADDR);

                if (xfers[i].flags & I2C_M_TEN)
                        ccmd->cmd0 |= CMD0_FIFO_IS_10B;

                if (xfers[i].flags & I2C_M_RD) {
                        ccmd->cmd0 |= CMD0_FIFO_RNW;
                        ccmd->rx_buf = xfers[i].buf;
                        ccmd->rx_len = xfers[i].len;
                } else {
                        ccmd->tx_buf = xfers[i].buf;
                        ccmd->tx_len = xfers[i].len;
                }
        }

        cdns_i3c_master_queue_xfer(master, xfer);
        if (!wait_for_completion_timeout(&xfer->comp, msecs_to_jiffies(1000)))
                cdns_i3c_master_unqueue_xfer(master, xfer);

        ret = xfer->ret;
        cdns_i3c_master_free_xfer(xfer);

        return ret;
}

struct cdns_i3c_i2c_dev_data {
        u16 id;
        s16 ibi;
        struct i3c_generic_ibi_pool *ibi_pool;
};

static u32 prepare_rr0_dev_address(u32 addr)
{
        u32 ret = (addr << 1) & 0xff;

        /* RR0[7:1] = addr[6:0] */
        ret |= (addr & GENMASK(6, 0)) << 1;

        /* RR0[15:13] = addr[9:7] */
        ret |= (addr & GENMASK(9, 7)) << 6;

        /* RR0[0] = ~XOR(addr[6:0]) */
        if (!(hweight8(addr & 0x7f) & 1))
                ret |= 1;

        return ret;
}

static void cdns_i3c_master_upd_i3c_addr(struct i3c_dev_desc *dev)
{
        struct i3c_master_controller *m = i3c_dev_get_master(dev);
        struct cdns_i3c_master *master = to_cdns_i3c_master(m);
        struct cdns_i3c_i2c_dev_data *data = i3c_dev_get_master_data(dev);
        u32 rr;

        rr = prepare_rr0_dev_address(dev->info.dyn_addr ?
                                     dev->info.dyn_addr :
                                     dev->info.static_addr);
        writel(DEV_ID_RR0_IS_I3C | rr, master->regs + DEV_ID_RR0(data->id));
}

static int cdns_i3c_master_get_rr_slot(struct cdns_i3c_master *master,
                                       u8 dyn_addr)
{
        unsigned long activedevs;
        u32 rr;
        int i;

        if (!dyn_addr) {
                if (!master->free_rr_slots)
                        return -ENOSPC;

                return ffs(master->free_rr_slots) - 1;
        }

        activedevs = readl(master->regs + DEVS_CTRL) & DEVS_CTRL_DEVS_ACTIVE_MASK;
        activedevs &= ~BIT(0);

        for_each_set_bit(i, &activedevs, master->maxdevs + 1) {
                rr = readl(master->regs + DEV_ID_RR0(i));
                if (!(rr & DEV_ID_RR0_IS_I3C) ||
                    DEV_ID_RR0_GET_DEV_ADDR(rr) != dyn_addr)
                        continue;

                return i;
        }

        return -EINVAL;
}

static int cdns_i3c_master_reattach_i3c_dev(struct i3c_dev_desc *dev,
                                            u8 old_dyn_addr)
{
        cdns_i3c_master_upd_i3c_addr(dev);

        return 0;
}

static int cdns_i3c_master_attach_i3c_dev(struct i3c_dev_desc *dev)
{
        struct i3c_master_controller *m = i3c_dev_get_master(dev);
        struct cdns_i3c_master *master = to_cdns_i3c_master(m);
        struct cdns_i3c_i2c_dev_data *data;
        int slot;

        data = kzalloc(sizeof(*data), GFP_KERNEL);
        if (!data)
                return -ENOMEM;

        slot = cdns_i3c_master_get_rr_slot(master, dev->info.dyn_addr);
        if (slot < 0) {
                kfree(data);
                return slot;
        }

        data->ibi = -1;
        data->id = slot;
        i3c_dev_set_master_data(dev, data);
        master->free_rr_slots &= ~BIT(slot);

        if (!dev->info.dyn_addr) {
                cdns_i3c_master_upd_i3c_addr(dev);
                writel(readl(master->regs + DEVS_CTRL) |
                       DEVS_CTRL_DEV_ACTIVE(data->id),
                       master->regs + DEVS_CTRL);
        }

        return 0;
}

static void cdns_i3c_master_detach_i3c_dev(struct i3c_dev_desc *dev)
{
        struct i3c_master_controller *m = i3c_dev_get_master(dev);
        struct cdns_i3c_master *master = to_cdns_i3c_master(m);
        struct cdns_i3c_i2c_dev_data *data = i3c_dev_get_master_data(dev);

        writel(readl(master->regs + DEVS_CTRL) |
               DEVS_CTRL_DEV_CLR(data->id),
               master->regs + DEVS_CTRL);

        i3c_dev_set_master_data(dev, NULL);
        master->free_rr_slots |= BIT(data->id);
        kfree(data);
}

static int cdns_i3c_master_attach_i2c_dev(struct i2c_dev_desc *dev)
{
        struct i3c_master_controller *m = i2c_dev_get_master(dev);
        struct cdns_i3c_master *master = to_cdns_i3c_master(m);
        struct cdns_i3c_i2c_dev_data *data;
        int slot;

        slot = cdns_i3c_master_get_rr_slot(master, 0);
        if (slot < 0)
                return slot;

        data = kzalloc(sizeof(*data), GFP_KERNEL);
        if (!data)
                return -ENOMEM;

        data->id = slot;
        master->free_rr_slots &= ~BIT(slot);
        i2c_dev_set_master_data(dev, data);

        writel(prepare_rr0_dev_address(dev->addr),
               master->regs + DEV_ID_RR0(data->id));
        writel(dev->lvr, master->regs + DEV_ID_RR2(data->id));
        writel(readl(master->regs + DEVS_CTRL) |
               DEVS_CTRL_DEV_ACTIVE(data->id),
               master->regs + DEVS_CTRL);

        return 0;
}

static void cdns_i3c_master_detach_i2c_dev(struct i2c_dev_desc *dev)
{
        struct i3c_master_controller *m = i2c_dev_get_master(dev);
        struct cdns_i3c_master *master = to_cdns_i3c_master(m);
        struct cdns_i3c_i2c_dev_data *data = i2c_dev_get_master_data(dev);

        writel(readl(master->regs + DEVS_CTRL) |
               DEVS_CTRL_DEV_CLR(data->id),
               master->regs + DEVS_CTRL);
        master->free_rr_slots |= BIT(data->id);

        i2c_dev_set_master_data(dev, NULL);
        kfree(data);
}

static void cdns_i3c_master_bus_cleanup(struct i3c_master_controller *m)
{
        struct cdns_i3c_master *master = to_cdns_i3c_master(m);

        cdns_i3c_master_disable(master);
}

static void cdns_i3c_master_dev_rr_to_info(struct cdns_i3c_master *master,
                                           unsigned int slot,
                                           struct i3c_device_info *info)
{
        u32 rr;

        memset(info, 0, sizeof(*info));
        rr = readl(master->regs + DEV_ID_RR0(slot));
        info->dyn_addr = DEV_ID_RR0_GET_DEV_ADDR(rr);
        rr = readl(master->regs + DEV_ID_RR2(slot));
        info->dcr = rr;
        info->bcr = rr >> 8;
        info->pid = rr >> 16;
        info->pid |= (u64)readl(master->regs + DEV_ID_RR1(slot)) << 16;
}

static void cdns_i3c_master_upd_i3c_scl_lim(struct cdns_i3c_master *master)
{
        struct i3c_master_controller *m = &master->base;
        unsigned long i3c_lim_period, pres_step, ncycles;
        struct i3c_bus *bus = i3c_master_get_bus(m);
        unsigned long new_i3c_scl_lim = 0;
        struct i3c_dev_desc *dev;
        u32 prescl1, ctrl;

        i3c_bus_for_each_i3cdev(bus, dev) {
                unsigned long max_fscl;

                max_fscl = max(I3C_CCC_MAX_SDR_FSCL(dev->info.max_read_ds),
                               I3C_CCC_MAX_SDR_FSCL(dev->info.max_write_ds));
                switch (max_fscl) {
                case I3C_SDR1_FSCL_8MHZ:
                        max_fscl = 8000000;
                        break;
                case I3C_SDR2_FSCL_6MHZ:
                        max_fscl = 6000000;
                        break;
                case I3C_SDR3_FSCL_4MHZ:
                        max_fscl = 4000000;
                        break;
                case I3C_SDR4_FSCL_2MHZ:
                        max_fscl = 2000000;
                        break;
                case I3C_SDR0_FSCL_MAX:
                default:
                        max_fscl = 0;
                        break;
                }

                if (max_fscl &&
                    (new_i3c_scl_lim > max_fscl || !new_i3c_scl_lim))
                        new_i3c_scl_lim = max_fscl;
        }

        /* Only update PRESCL_CTRL1 if the I3C SCL limitation has changed. */
        if (new_i3c_scl_lim == master->i3c_scl_lim)
                return;
        master->i3c_scl_lim = new_i3c_scl_lim;
        if (!new_i3c_scl_lim)
                return;
        pres_step = 1000000000UL / (bus->scl_rate.i3c * 4);

        /* Configure PP_LOW to meet I3C slave limitations. */
        prescl1 = readl(master->regs + PRESCL_CTRL1) &
                  ~PRESCL_CTRL1_PP_LOW_MASK;
        ctrl = readl(master->regs + CTRL);

        i3c_lim_period = DIV_ROUND_UP(1000000000, master->i3c_scl_lim);
        ncycles = DIV_ROUND_UP(i3c_lim_period, pres_step);
        if (ncycles < 4)
                ncycles = 0;
        else
                ncycles -= 4;

        prescl1 |= PRESCL_CTRL1_PP_LOW(ncycles);

        /* Disable I3C master before updating PRESCL_CTRL1. */
        if (ctrl & CTRL_DEV_EN)
                cdns_i3c_master_disable(master);

        writel(prescl1, master->regs + PRESCL_CTRL1);

        if (ctrl & CTRL_DEV_EN)
                cdns_i3c_master_enable(master);
}

static int cdns_i3c_master_do_daa(struct i3c_master_controller *m)
{
        struct cdns_i3c_master *master = to_cdns_i3c_master(m);
        unsigned long olddevs, newdevs;
        int ret, slot;
        u8 addrs[MAX_DEVS] = { };
        u8 last_addr = 0;

        olddevs = readl(master->regs + DEVS_CTRL) & DEVS_CTRL_DEVS_ACTIVE_MASK;
        olddevs |= BIT(0);

        /* Prepare RR slots before launching DAA. */
        for_each_clear_bit(slot, &olddevs, master->maxdevs + 1) {
                ret = i3c_master_get_free_addr(m, last_addr + 1);
                if (ret < 0)
                        return -ENOSPC;

                last_addr = ret;
                addrs[slot] = last_addr;
                writel(prepare_rr0_dev_address(last_addr) | DEV_ID_RR0_IS_I3C,
                       master->regs + DEV_ID_RR0(slot));
                writel(0, master->regs + DEV_ID_RR1(slot));
                writel(0, master->regs + DEV_ID_RR2(slot));
        }

        ret = i3c_master_entdaa_locked(&master->base);
        if (ret && ret != I3C_ERROR_M2)
                return ret;

        newdevs = readl(master->regs + DEVS_CTRL) & DEVS_CTRL_DEVS_ACTIVE_MASK;
        newdevs &= ~olddevs;

        /*
         * Clear all retaining registers filled during DAA. We already
         * have the addressed assigned to them in the addrs array.
         */
        for_each_set_bit(slot, &newdevs, master->maxdevs + 1)
                i3c_master_add_i3c_dev_locked(m, addrs[slot]);

        /*
         * Clear slots that ended up not being used. Can be caused by I3C
         * device creation failure or when the I3C device was already known
         * by the system but with a different address (in this case the device
         * already has a slot and does not need a new one).
         */
        writel(readl(master->regs + DEVS_CTRL) |
               master->free_rr_slots << DEVS_CTRL_DEV_CLR_SHIFT,
               master->regs + DEVS_CTRL);

        i3c_master_defslvs_locked(&master->base);

        cdns_i3c_master_upd_i3c_scl_lim(master);

        /* Unmask Hot-Join and Mastership request interrupts. */
        i3c_master_enec_locked(m, I3C_BROADCAST_ADDR,
                               I3C_CCC_EVENT_HJ | I3C_CCC_EVENT_MR);

        return 0;
}

static u8 cdns_i3c_master_calculate_thd_delay(struct cdns_i3c_master *master)
{
        unsigned long sysclk_rate = clk_get_rate(master->sysclk);
        u8 thd_delay = DIV_ROUND_UP(master->devdata->thd_delay_ns,
                                    (NSEC_PER_SEC / sysclk_rate));

        /* Every value greater than 3 is not valid. */
        if (thd_delay > THD_DELAY_MAX)
                thd_delay = THD_DELAY_MAX;

        /* CTLR_THD_DEL value is encoded. */
        return (THD_DELAY_MAX - thd_delay);
}

static int cdns_i3c_master_bus_init(struct i3c_master_controller *m)
{
        struct cdns_i3c_master *master = to_cdns_i3c_master(m);
        unsigned long pres_step, sysclk_rate, max_i2cfreq;
        struct i3c_bus *bus = i3c_master_get_bus(m);
        u32 ctrl, prescl0, prescl1, pres, low;
        struct i3c_device_info info = { };
        int ret, ncycles;

        switch (bus->mode) {
        case I3C_BUS_MODE_PURE:
                ctrl = CTRL_PURE_BUS_MODE;
                break;

        case I3C_BUS_MODE_MIXED_FAST:
                ctrl = CTRL_MIXED_FAST_BUS_MODE;
                break;

        case I3C_BUS_MODE_MIXED_SLOW:
                ctrl = CTRL_MIXED_SLOW_BUS_MODE;
                break;

        default:
                return -EINVAL;
        }

        sysclk_rate = clk_get_rate(master->sysclk);
        if (!sysclk_rate)
                return -EINVAL;

        pres = DIV_ROUND_UP(sysclk_rate, (bus->scl_rate.i3c * 4)) - 1;
        if (pres > PRESCL_CTRL0_MAX)
                return -ERANGE;

        bus->scl_rate.i3c = sysclk_rate / ((pres + 1) * 4);

        prescl0 = PRESCL_CTRL0_I3C(pres);

        low = ((I3C_BUS_TLOW_OD_MIN_NS * sysclk_rate) / (pres + 1)) - 2;
        prescl1 = PRESCL_CTRL1_OD_LOW(low);

        max_i2cfreq = bus->scl_rate.i2c;

        pres = (sysclk_rate / (max_i2cfreq * 5)) - 1;
        if (pres > PRESCL_CTRL0_MAX)
                return -ERANGE;

        bus->scl_rate.i2c = sysclk_rate / ((pres + 1) * 5);

        prescl0 |= PRESCL_CTRL0_I2C(pres);
        writel(prescl0, master->regs + PRESCL_CTRL0);

        /* Calculate OD and PP low. */
        pres_step = 1000000000 / (bus->scl_rate.i3c * 4);
        ncycles = DIV_ROUND_UP(I3C_BUS_TLOW_OD_MIN_NS, pres_step) - 2;
        if (ncycles < 0)
                ncycles = 0;
        prescl1 = PRESCL_CTRL1_OD_LOW(ncycles);
        writel(prescl1, master->regs + PRESCL_CTRL1);

        /* Get an address for the master. */
        ret = i3c_master_get_free_addr(m, 0);
        if (ret < 0)
                return ret;

        writel(prepare_rr0_dev_address(ret) | DEV_ID_RR0_IS_I3C,
               master->regs + DEV_ID_RR0(0));

        cdns_i3c_master_dev_rr_to_info(master, 0, &info);
        if (info.bcr & I3C_BCR_HDR_CAP)
                info.hdr_cap = I3C_CCC_HDR_MODE(I3C_HDR_DDR);

        ret = i3c_master_set_info(&master->base, &info);
        if (ret)
                return ret;

        /*
         * Enable Hot-Join, and, when a Hot-Join request happens, disable all
         * events coming from this device.
         *
         * We will issue ENTDAA afterwards from the threaded IRQ handler.
         */
        ctrl |= CTRL_HJ_ACK | CTRL_HJ_DISEC | CTRL_HALT_EN | CTRL_MCS_EN;

        /*
         * Configure data hold delay based on device-specific data.
         *
         * MIPI I3C Specification 1.0 defines non-zero minimal tHD_PP timing on
         * master output. This setting allows to meet this timing on master's
         * SoC outputs, regardless of PCB balancing.
         */
        ctrl |= CTRL_THD_DELAY(cdns_i3c_master_calculate_thd_delay(master));
        writel(ctrl, master->regs + CTRL);

        cdns_i3c_master_enable(master);

        return 0;
}

static void cdns_i3c_master_handle_ibi(struct cdns_i3c_master *master,
                                       u32 ibir)
{
        struct cdns_i3c_i2c_dev_data *data;
        bool data_consumed = false;
        struct i3c_ibi_slot *slot;
        u32 id = IBIR_SLVID(ibir);
        struct i3c_dev_desc *dev;
        size_t nbytes;
        u8 *buf;

        /*
         * FIXME: maybe we should report the FIFO OVF errors to the upper
         * layer.
         */
        if (id >= master->ibi.num_slots || (ibir & IBIR_ERROR))
                goto out;

        dev = master->ibi.slots[id];
        spin_lock(&master->ibi.lock);

        data = i3c_dev_get_master_data(dev);
        slot = i3c_generic_ibi_get_free_slot(data->ibi_pool);
        if (!slot)
                goto out_unlock;

        buf = slot->data;

        nbytes = IBIR_XFER_BYTES(ibir);
        readsl(master->regs + IBI_DATA_FIFO, buf, nbytes / 4);
        if (nbytes % 3) {
                u32 tmp = __raw_readl(master->regs + IBI_DATA_FIFO);

                memcpy(buf + (nbytes & ~3), &tmp, nbytes & 3);
        }

        slot->len = min_t(unsigned int, IBIR_XFER_BYTES(ibir),
                          dev->ibi->max_payload_len);
        i3c_master_queue_ibi(dev, slot);
        data_consumed = true;

out_unlock:
        spin_unlock(&master->ibi.lock);

out:
        /* Consume data from the FIFO if it's not been done already. */
        if (!data_consumed) {
                int i;

                for (i = 0; i < IBIR_XFER_BYTES(ibir); i += 4)
                        readl(master->regs + IBI_DATA_FIFO);
        }
}

static void cnds_i3c_master_demux_ibis(struct cdns_i3c_master *master)
{
        u32 status0;

        writel(MST_INT_IBIR_THR, master->regs + MST_ICR);

        for (status0 = readl(master->regs + MST_STATUS0);
             !(status0 & MST_STATUS0_IBIR_EMP);
             status0 = readl(master->regs + MST_STATUS0)) {
                u32 ibir = readl(master->regs + IBIR);

                switch (IBIR_TYPE(ibir)) {
                case IBIR_TYPE_IBI:
                        cdns_i3c_master_handle_ibi(master, ibir);
                        break;

                case IBIR_TYPE_HJ:
                        WARN_ON(IBIR_XFER_BYTES(ibir) || (ibir & IBIR_ERROR));
                        queue_work(master->base.wq, &master->hj_work);
                        break;

                case IBIR_TYPE_MR:
                        WARN_ON(IBIR_XFER_BYTES(ibir) || (ibir & IBIR_ERROR));
                        break;

                default:
                        break;
                }
        }
}

static irqreturn_t cdns_i3c_master_interrupt(int irq, void *data)
{
        struct cdns_i3c_master *master = data;
        u32 status;

        status = readl(master->regs + MST_ISR);
        if (!(status & readl(master->regs + MST_IMR)))
                return IRQ_NONE;

        spin_lock(&master->xferqueue.lock);
        cdns_i3c_master_end_xfer_locked(master, status);
        spin_unlock(&master->xferqueue.lock);

        if (status & MST_INT_IBIR_THR)
                cnds_i3c_master_demux_ibis(master);

        return IRQ_HANDLED;
}

static int cdns_i3c_master_disable_ibi(struct i3c_dev_desc *dev)
{
        struct i3c_master_controller *m = i3c_dev_get_master(dev);
        struct cdns_i3c_master *master = to_cdns_i3c_master(m);
        struct cdns_i3c_i2c_dev_data *data = i3c_dev_get_master_data(dev);
        unsigned long flags;
        u32 sirmap;
        int ret;

        ret = i3c_master_disec_locked(m, dev->info.dyn_addr,
                                      I3C_CCC_EVENT_SIR);
        if (ret)
                return ret;

        spin_lock_irqsave(&master->ibi.lock, flags);
        sirmap = readl(master->regs + SIR_MAP_DEV_REG(data->ibi));
        sirmap &= ~SIR_MAP_DEV_CONF_MASK(data->ibi);
        sirmap |= SIR_MAP_DEV_CONF(data->ibi,
                                   SIR_MAP_DEV_DA(I3C_BROADCAST_ADDR));
        writel(sirmap, master->regs + SIR_MAP_DEV_REG(data->ibi));
        spin_unlock_irqrestore(&master->ibi.lock, flags);

        return ret;
}

static int cdns_i3c_master_enable_ibi(struct i3c_dev_desc *dev)
{
        struct i3c_master_controller *m = i3c_dev_get_master(dev);
        struct cdns_i3c_master *master = to_cdns_i3c_master(m);
        struct cdns_i3c_i2c_dev_data *data = i3c_dev_get_master_data(dev);
        unsigned long flags;
        u32 sircfg, sirmap;
        int ret;

        spin_lock_irqsave(&master->ibi.lock, flags);
        sirmap = readl(master->regs + SIR_MAP_DEV_REG(data->ibi));
        sirmap &= ~SIR_MAP_DEV_CONF_MASK(data->ibi);
        sircfg = SIR_MAP_DEV_ROLE(dev->info.bcr >> 6) |
                 SIR_MAP_DEV_DA(dev->info.dyn_addr) |
                 SIR_MAP_DEV_PL(dev->info.max_ibi_len) |
                 SIR_MAP_DEV_ACK;

        if (dev->info.bcr & I3C_BCR_MAX_DATA_SPEED_LIM)
                sircfg |= SIR_MAP_DEV_SLOW;

        sirmap |= SIR_MAP_DEV_CONF(data->ibi, sircfg);
        writel(sirmap, master->regs + SIR_MAP_DEV_REG(data->ibi));
        spin_unlock_irqrestore(&master->ibi.lock, flags);

        ret = i3c_master_enec_locked(m, dev->info.dyn_addr,
                                     I3C_CCC_EVENT_SIR);
        if (ret) {
                spin_lock_irqsave(&master->ibi.lock, flags);
                sirmap = readl(master->regs + SIR_MAP_DEV_REG(data->ibi));
                sirmap &= ~SIR_MAP_DEV_CONF_MASK(data->ibi);
                sirmap |= SIR_MAP_DEV_CONF(data->ibi,
                                           SIR_MAP_DEV_DA(I3C_BROADCAST_ADDR));
                writel(sirmap, master->regs + SIR_MAP_DEV_REG(data->ibi));
                spin_unlock_irqrestore(&master->ibi.lock, flags);
        }

        return ret;
}

static int cdns_i3c_master_request_ibi(struct i3c_dev_desc *dev,
                                       const struct i3c_ibi_setup *req)
{
        struct i3c_master_controller *m = i3c_dev_get_master(dev);
        struct cdns_i3c_master *master = to_cdns_i3c_master(m);
        struct cdns_i3c_i2c_dev_data *data = i3c_dev_get_master_data(dev);
        unsigned long flags;
        unsigned int i;

        data->ibi_pool = i3c_generic_ibi_alloc_pool(dev, req);
        if (IS_ERR(data->ibi_pool))
                return PTR_ERR(data->ibi_pool);

        spin_lock_irqsave(&master->ibi.lock, flags);
        for (i = 0; i < master->ibi.num_slots; i++) {
                if (!master->ibi.slots[i]) {
                        data->ibi = i;
                        master->ibi.slots[i] = dev;
                        break;
                }
        }
        spin_unlock_irqrestore(&master->ibi.lock, flags);

        if (i < master->ibi.num_slots)
                return 0;

        i3c_generic_ibi_free_pool(data->ibi_pool);
        data->ibi_pool = NULL;

        return -ENOSPC;
}

static void cdns_i3c_master_free_ibi(struct i3c_dev_desc *dev)
{
        struct i3c_master_controller *m = i3c_dev_get_master(dev);
        struct cdns_i3c_master *master = to_cdns_i3c_master(m);
        struct cdns_i3c_i2c_dev_data *data = i3c_dev_get_master_data(dev);
        unsigned long flags;

        spin_lock_irqsave(&master->ibi.lock, flags);
        master->ibi.slots[data->ibi] = NULL;
        data->ibi = -1;
        spin_unlock_irqrestore(&master->ibi.lock, flags);

        i3c_generic_ibi_free_pool(data->ibi_pool);
}

static void cdns_i3c_master_recycle_ibi_slot(struct i3c_dev_desc *dev,
                                             struct i3c_ibi_slot *slot)
{
        struct cdns_i3c_i2c_dev_data *data = i3c_dev_get_master_data(dev);

        i3c_generic_ibi_recycle_slot(data->ibi_pool, slot);
}

static const struct i3c_master_controller_ops cdns_i3c_master_ops = {
        .bus_init = cdns_i3c_master_bus_init,
        .bus_cleanup = cdns_i3c_master_bus_cleanup,
        .do_daa = cdns_i3c_master_do_daa,
        .attach_i3c_dev = cdns_i3c_master_attach_i3c_dev,
        .reattach_i3c_dev = cdns_i3c_master_reattach_i3c_dev,
        .detach_i3c_dev = cdns_i3c_master_detach_i3c_dev,
        .attach_i2c_dev = cdns_i3c_master_attach_i2c_dev,
        .detach_i2c_dev = cdns_i3c_master_detach_i2c_dev,
        .supports_ccc_cmd = cdns_i3c_master_supports_ccc_cmd,
        .send_ccc_cmd = cdns_i3c_master_send_ccc_cmd,
        .priv_xfers = cdns_i3c_master_priv_xfers,
        .i2c_xfers = cdns_i3c_master_i2c_xfers,
        .enable_ibi = cdns_i3c_master_enable_ibi,
        .disable_ibi = cdns_i3c_master_disable_ibi,
        .request_ibi = cdns_i3c_master_request_ibi,
        .free_ibi = cdns_i3c_master_free_ibi,
        .recycle_ibi_slot = cdns_i3c_master_recycle_ibi_slot,
};

static void cdns_i3c_master_hj(struct work_struct *work)
{
        struct cdns_i3c_master *master = container_of(work,
                                                      struct cdns_i3c_master,
                                                      hj_work);

        i3c_master_do_daa(&master->base);
}

static struct cdns_i3c_data cdns_i3c_devdata = {
        .thd_delay_ns = 10,
};

static const struct of_device_id cdns_i3c_master_of_ids[] = {
        { .compatible = "cdns,i3c-master", .data = &cdns_i3c_devdata },
        { /* sentinel */ },
};

static int cdns_i3c_master_probe(struct platform_device *pdev)
{
        struct cdns_i3c_master *master;
        int ret, irq;
        u32 val;

        master = devm_kzalloc(&pdev->dev, sizeof(*master), GFP_KERNEL);
        if (!master)
                return -ENOMEM;

        master->devdata = of_device_get_match_data(&pdev->dev);
        if (!master->devdata)
                return -EINVAL;

        master->regs = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(master->regs))
                return PTR_ERR(master->regs);

        master->pclk = devm_clk_get(&pdev->dev, "pclk");
        if (IS_ERR(master->pclk))
                return PTR_ERR(master->pclk);

        master->sysclk = devm_clk_get(&pdev->dev, "sysclk");
        if (IS_ERR(master->sysclk))
                return PTR_ERR(master->sysclk);

        irq = platform_get_irq(pdev, 0);
        if (irq < 0)
                return irq;

        ret = clk_prepare_enable(master->pclk);
        if (ret)
                return ret;

        ret = clk_prepare_enable(master->sysclk);
        if (ret)
                goto err_disable_pclk;

        if (readl(master->regs + DEV_ID) != DEV_ID_I3C_MASTER) {
                ret = -EINVAL;
                goto err_disable_sysclk;
        }

        spin_lock_init(&master->xferqueue.lock);
        INIT_LIST_HEAD(&master->xferqueue.list);

        INIT_WORK(&master->hj_work, cdns_i3c_master_hj);
        writel(0xffffffff, master->regs + MST_IDR);
        writel(0xffffffff, master->regs + SLV_IDR);
        ret = devm_request_irq(&pdev->dev, irq, cdns_i3c_master_interrupt, 0,
                               dev_name(&pdev->dev), master);
        if (ret)
                goto err_disable_sysclk;

        platform_set_drvdata(pdev, master);

        val = readl(master->regs + CONF_STATUS0);

        /* Device ID0 is reserved to describe this master. */
        master->maxdevs = CONF_STATUS0_DEVS_NUM(val);
        master->free_rr_slots = GENMASK(master->maxdevs, 1);

        val = readl(master->regs + CONF_STATUS1);
        master->caps.cmdfifodepth = CONF_STATUS1_CMD_DEPTH(val);
        master->caps.rxfifodepth = CONF_STATUS1_RX_DEPTH(val);
        master->caps.txfifodepth = CONF_STATUS1_TX_DEPTH(val);
        master->caps.ibirfifodepth = CONF_STATUS0_IBIR_DEPTH(val);
        master->caps.cmdrfifodepth = CONF_STATUS0_CMDR_DEPTH(val);

        spin_lock_init(&master->ibi.lock);
        master->ibi.num_slots = CONF_STATUS1_IBI_HW_RES(val);
        master->ibi.slots = devm_kcalloc(&pdev->dev, master->ibi.num_slots,
                                         sizeof(*master->ibi.slots),
                                         GFP_KERNEL);
        if (!master->ibi.slots) {
                ret = -ENOMEM;
                goto err_disable_sysclk;
        }

        writel(IBIR_THR(1), master->regs + CMD_IBI_THR_CTRL);
        writel(MST_INT_IBIR_THR, master->regs + MST_IER);
        writel(DEVS_CTRL_DEV_CLR_ALL, master->regs + DEVS_CTRL);

        ret = i3c_master_register(&master->base, &pdev->dev,
                                  &cdns_i3c_master_ops, false);
        if (ret)
                goto err_disable_sysclk;

        return 0;

err_disable_sysclk:
        clk_disable_unprepare(master->sysclk);

err_disable_pclk:
        clk_disable_unprepare(master->pclk);

        return ret;
}

static int cdns_i3c_master_remove(struct platform_device *pdev)
{
        struct cdns_i3c_master *master = platform_get_drvdata(pdev);
        int ret;

        ret = i3c_master_unregister(&master->base);
        if (ret)
                return ret;

        clk_disable_unprepare(master->sysclk);
        clk_disable_unprepare(master->pclk);

        return 0;
}

static struct platform_driver cdns_i3c_master = {
        .probe = cdns_i3c_master_probe,
        .remove = cdns_i3c_master_remove,
        .driver = {
                .name = "cdns-i3c-master",
                .of_match_table = cdns_i3c_master_of_ids,
        },
};
module_platform_driver(cdns_i3c_master);

MODULE_AUTHOR("Boris Brezillon <boris.brezillon@bootlin.com>");
MODULE_DESCRIPTION("Cadence I3C master driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:cdns-i3c-master");