linux/drivers/spi/spi-dw-mmio.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Memory-mapped interface driver for DW SPI Core
   4 *
   5 * Copyright (c) 2010, Octasic semiconductor.
   6 */
   7
   8#include <linux/clk.h>
   9#include <linux/err.h>
  10#include <linux/platform_device.h>
  11#include <linux/pm_runtime.h>
  12#include <linux/slab.h>
  13#include <linux/spi/spi.h>
  14#include <linux/scatterlist.h>
  15#include <linux/mfd/syscon.h>
  16#include <linux/module.h>
  17#include <linux/of.h>
  18#include <linux/of_platform.h>
  19#include <linux/acpi.h>
  20#include <linux/property.h>
  21#include <linux/regmap.h>
  22#include <linux/reset.h>
  23
  24#include "spi-dw.h"
  25
  26#define DRIVER_NAME "dw_spi_mmio"
  27
  28struct dw_spi_mmio {
  29        struct dw_spi  dws;
  30        struct clk     *clk;
  31        struct clk     *pclk;
  32        void           *priv;
  33        struct reset_control *rstc;
  34};
  35
  36#define MSCC_CPU_SYSTEM_CTRL_GENERAL_CTRL       0x24
  37#define OCELOT_IF_SI_OWNER_OFFSET               4
  38#define JAGUAR2_IF_SI_OWNER_OFFSET              6
  39#define MSCC_IF_SI_OWNER_MASK                   GENMASK(1, 0)
  40#define MSCC_IF_SI_OWNER_SISL                   0
  41#define MSCC_IF_SI_OWNER_SIBM                   1
  42#define MSCC_IF_SI_OWNER_SIMC                   2
  43
  44#define MSCC_SPI_MST_SW_MODE                    0x14
  45#define MSCC_SPI_MST_SW_MODE_SW_PIN_CTRL_MODE   BIT(13)
  46#define MSCC_SPI_MST_SW_MODE_SW_SPI_CS(x)       (x << 5)
  47
  48/*
  49 * For Keem Bay, CTRLR0[31] is used to select controller mode.
  50 * 0: SSI is slave
  51 * 1: SSI is master
  52 */
  53#define KEEMBAY_CTRLR0_SSIC_IS_MST              BIT(31)
  54
  55struct dw_spi_mscc {
  56        struct regmap       *syscon;
  57        void __iomem        *spi_mst;
  58};
  59
  60/*
  61 * The Designware SPI controller (referred to as master in the documentation)
  62 * automatically deasserts chip select when the tx fifo is empty. The chip
  63 * selects then needs to be either driven as GPIOs or, for the first 4 using the
  64 * the SPI boot controller registers. the final chip select is an OR gate
  65 * between the Designware SPI controller and the SPI boot controller.
  66 */
  67static void dw_spi_mscc_set_cs(struct spi_device *spi, bool enable)
  68{
  69        struct dw_spi *dws = spi_master_get_devdata(spi->master);
  70        struct dw_spi_mmio *dwsmmio = container_of(dws, struct dw_spi_mmio, dws);
  71        struct dw_spi_mscc *dwsmscc = dwsmmio->priv;
  72        u32 cs = spi->chip_select;
  73
  74        if (cs < 4) {
  75                u32 sw_mode = MSCC_SPI_MST_SW_MODE_SW_PIN_CTRL_MODE;
  76
  77                if (!enable)
  78                        sw_mode |= MSCC_SPI_MST_SW_MODE_SW_SPI_CS(BIT(cs));
  79
  80                writel(sw_mode, dwsmscc->spi_mst + MSCC_SPI_MST_SW_MODE);
  81        }
  82
  83        dw_spi_set_cs(spi, enable);
  84}
  85
  86static int dw_spi_mscc_init(struct platform_device *pdev,
  87                            struct dw_spi_mmio *dwsmmio,
  88                            const char *cpu_syscon, u32 if_si_owner_offset)
  89{
  90        struct dw_spi_mscc *dwsmscc;
  91
  92        dwsmscc = devm_kzalloc(&pdev->dev, sizeof(*dwsmscc), GFP_KERNEL);
  93        if (!dwsmscc)
  94                return -ENOMEM;
  95
  96        dwsmscc->spi_mst = devm_platform_ioremap_resource(pdev, 1);
  97        if (IS_ERR(dwsmscc->spi_mst)) {
  98                dev_err(&pdev->dev, "SPI_MST region map failed\n");
  99                return PTR_ERR(dwsmscc->spi_mst);
 100        }
 101
 102        dwsmscc->syscon = syscon_regmap_lookup_by_compatible(cpu_syscon);
 103        if (IS_ERR(dwsmscc->syscon))
 104                return PTR_ERR(dwsmscc->syscon);
 105
 106        /* Deassert all CS */
 107        writel(0, dwsmscc->spi_mst + MSCC_SPI_MST_SW_MODE);
 108
 109        /* Select the owner of the SI interface */
 110        regmap_update_bits(dwsmscc->syscon, MSCC_CPU_SYSTEM_CTRL_GENERAL_CTRL,
 111                           MSCC_IF_SI_OWNER_MASK << if_si_owner_offset,
 112                           MSCC_IF_SI_OWNER_SIMC << if_si_owner_offset);
 113
 114        dwsmmio->dws.set_cs = dw_spi_mscc_set_cs;
 115        dwsmmio->priv = dwsmscc;
 116
 117        /* Register hook to configure CTRLR0 */
 118        dwsmmio->dws.update_cr0 = dw_spi_update_cr0;
 119
 120        return 0;
 121}
 122
 123static int dw_spi_mscc_ocelot_init(struct platform_device *pdev,
 124                                   struct dw_spi_mmio *dwsmmio)
 125{
 126        return dw_spi_mscc_init(pdev, dwsmmio, "mscc,ocelot-cpu-syscon",
 127                                OCELOT_IF_SI_OWNER_OFFSET);
 128}
 129
 130static int dw_spi_mscc_jaguar2_init(struct platform_device *pdev,
 131                                    struct dw_spi_mmio *dwsmmio)
 132{
 133        return dw_spi_mscc_init(pdev, dwsmmio, "mscc,jaguar2-cpu-syscon",
 134                                JAGUAR2_IF_SI_OWNER_OFFSET);
 135}
 136
 137static int dw_spi_alpine_init(struct platform_device *pdev,
 138                              struct dw_spi_mmio *dwsmmio)
 139{
 140        dwsmmio->dws.cs_override = 1;
 141
 142        /* Register hook to configure CTRLR0 */
 143        dwsmmio->dws.update_cr0 = dw_spi_update_cr0;
 144
 145        return 0;
 146}
 147
 148static int dw_spi_dw_apb_init(struct platform_device *pdev,
 149                              struct dw_spi_mmio *dwsmmio)
 150{
 151        /* Register hook to configure CTRLR0 */
 152        dwsmmio->dws.update_cr0 = dw_spi_update_cr0;
 153
 154        dw_spi_dma_setup_generic(&dwsmmio->dws);
 155
 156        return 0;
 157}
 158
 159static int dw_spi_dwc_ssi_init(struct platform_device *pdev,
 160                               struct dw_spi_mmio *dwsmmio)
 161{
 162        /* Register hook to configure CTRLR0 */
 163        dwsmmio->dws.update_cr0 = dw_spi_update_cr0_v1_01a;
 164
 165        dw_spi_dma_setup_generic(&dwsmmio->dws);
 166
 167        return 0;
 168}
 169
 170static u32 dw_spi_update_cr0_keembay(struct spi_controller *master,
 171                                     struct spi_device *spi,
 172                                     struct spi_transfer *transfer)
 173{
 174        u32 cr0 = dw_spi_update_cr0_v1_01a(master, spi, transfer);
 175
 176        return cr0 | KEEMBAY_CTRLR0_SSIC_IS_MST;
 177}
 178
 179static int dw_spi_keembay_init(struct platform_device *pdev,
 180                               struct dw_spi_mmio *dwsmmio)
 181{
 182        /* Register hook to configure CTRLR0 */
 183        dwsmmio->dws.update_cr0 = dw_spi_update_cr0_keembay;
 184
 185        return 0;
 186}
 187
 188static int dw_spi_mmio_probe(struct platform_device *pdev)
 189{
 190        int (*init_func)(struct platform_device *pdev,
 191                         struct dw_spi_mmio *dwsmmio);
 192        struct dw_spi_mmio *dwsmmio;
 193        struct resource *mem;
 194        struct dw_spi *dws;
 195        int ret;
 196        int num_cs;
 197
 198        dwsmmio = devm_kzalloc(&pdev->dev, sizeof(struct dw_spi_mmio),
 199                        GFP_KERNEL);
 200        if (!dwsmmio)
 201                return -ENOMEM;
 202
 203        dws = &dwsmmio->dws;
 204
 205        /* Get basic io resource and map it */
 206        dws->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &mem);
 207        if (IS_ERR(dws->regs))
 208                return PTR_ERR(dws->regs);
 209
 210        dws->paddr = mem->start;
 211
 212        dws->irq = platform_get_irq(pdev, 0);
 213        if (dws->irq < 0)
 214                return dws->irq; /* -ENXIO */
 215
 216        dwsmmio->clk = devm_clk_get(&pdev->dev, NULL);
 217        if (IS_ERR(dwsmmio->clk))
 218                return PTR_ERR(dwsmmio->clk);
 219        ret = clk_prepare_enable(dwsmmio->clk);
 220        if (ret)
 221                return ret;
 222
 223        /* Optional clock needed to access the registers */
 224        dwsmmio->pclk = devm_clk_get_optional(&pdev->dev, "pclk");
 225        if (IS_ERR(dwsmmio->pclk)) {
 226                ret = PTR_ERR(dwsmmio->pclk);
 227                goto out_clk;
 228        }
 229        ret = clk_prepare_enable(dwsmmio->pclk);
 230        if (ret)
 231                goto out_clk;
 232
 233        /* find an optional reset controller */
 234        dwsmmio->rstc = devm_reset_control_get_optional_exclusive(&pdev->dev, "spi");
 235        if (IS_ERR(dwsmmio->rstc)) {
 236                ret = PTR_ERR(dwsmmio->rstc);
 237                goto out_clk;
 238        }
 239        reset_control_deassert(dwsmmio->rstc);
 240
 241        dws->bus_num = pdev->id;
 242
 243        dws->max_freq = clk_get_rate(dwsmmio->clk);
 244
 245        device_property_read_u32(&pdev->dev, "reg-io-width", &dws->reg_io_width);
 246
 247        num_cs = 4;
 248
 249        device_property_read_u32(&pdev->dev, "num-cs", &num_cs);
 250
 251        dws->num_cs = num_cs;
 252
 253        init_func = device_get_match_data(&pdev->dev);
 254        if (init_func) {
 255                ret = init_func(pdev, dwsmmio);
 256                if (ret)
 257                        goto out;
 258        }
 259
 260        pm_runtime_enable(&pdev->dev);
 261
 262        ret = dw_spi_add_host(&pdev->dev, dws);
 263        if (ret)
 264                goto out;
 265
 266        platform_set_drvdata(pdev, dwsmmio);
 267        return 0;
 268
 269out:
 270        pm_runtime_disable(&pdev->dev);
 271        clk_disable_unprepare(dwsmmio->pclk);
 272out_clk:
 273        clk_disable_unprepare(dwsmmio->clk);
 274        reset_control_assert(dwsmmio->rstc);
 275
 276        return ret;
 277}
 278
 279static int dw_spi_mmio_remove(struct platform_device *pdev)
 280{
 281        struct dw_spi_mmio *dwsmmio = platform_get_drvdata(pdev);
 282
 283        dw_spi_remove_host(&dwsmmio->dws);
 284        pm_runtime_disable(&pdev->dev);
 285        clk_disable_unprepare(dwsmmio->pclk);
 286        clk_disable_unprepare(dwsmmio->clk);
 287        reset_control_assert(dwsmmio->rstc);
 288
 289        return 0;
 290}
 291
 292static const struct of_device_id dw_spi_mmio_of_match[] = {
 293        { .compatible = "snps,dw-apb-ssi", .data = dw_spi_dw_apb_init},
 294        { .compatible = "mscc,ocelot-spi", .data = dw_spi_mscc_ocelot_init},
 295        { .compatible = "mscc,jaguar2-spi", .data = dw_spi_mscc_jaguar2_init},
 296        { .compatible = "amazon,alpine-dw-apb-ssi", .data = dw_spi_alpine_init},
 297        { .compatible = "renesas,rzn1-spi", .data = dw_spi_dw_apb_init},
 298        { .compatible = "snps,dwc-ssi-1.01a", .data = dw_spi_dwc_ssi_init},
 299        { .compatible = "intel,keembay-ssi", .data = dw_spi_keembay_init},
 300        { /* end of table */}
 301};
 302MODULE_DEVICE_TABLE(of, dw_spi_mmio_of_match);
 303
 304#ifdef CONFIG_ACPI
 305static const struct acpi_device_id dw_spi_mmio_acpi_match[] = {
 306        {"HISI0173", (kernel_ulong_t)dw_spi_dw_apb_init},
 307        {},
 308};
 309MODULE_DEVICE_TABLE(acpi, dw_spi_mmio_acpi_match);
 310#endif
 311
 312static struct platform_driver dw_spi_mmio_driver = {
 313        .probe          = dw_spi_mmio_probe,
 314        .remove         = dw_spi_mmio_remove,
 315        .driver         = {
 316                .name   = DRIVER_NAME,
 317                .of_match_table = dw_spi_mmio_of_match,
 318                .acpi_match_table = ACPI_PTR(dw_spi_mmio_acpi_match),
 319        },
 320};
 321module_platform_driver(dw_spi_mmio_driver);
 322
 323MODULE_AUTHOR("Jean-Hugues Deschenes <jean-hugues.deschenes@octasic.com>");
 324MODULE_DESCRIPTION("Memory-mapped I/O interface driver for DW SPI Core");
 325MODULE_LICENSE("GPL v2");
 326