LXR linux/drivers/tty/serial/cpm_uart/cpm_uart

   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 *  Driver for CPM (SCC/SMC) serial ports; CPM2 definitions
   4 *
   5 *  Maintainer: Kumar Gala (galak@kernel.crashing.org) (CPM2)
   6 *              Pantelis Antoniou (panto@intracom.gr) (CPM1)
   7 *
   8 *  Copyright (C) 2004 Freescale Semiconductor, Inc.
   9 *            (C) 2004 Intracom, S.A.
  10 *            (C) 2006 MontaVista Software, Inc.
  11 *              Vitaly Bordug <vbordug@ru.mvista.com>
  12 */
  13
  14#include <linux/module.h>
  15#include <linux/tty.h>
  16#include <linux/ioport.h>
  17#include <linux/slab.h>
  18#include <linux/serial.h>
  19#include <linux/console.h>
  20#include <linux/sysrq.h>
  21#include <linux/device.h>
  22#include <linux/memblock.h>
  23#include <linux/dma-mapping.h>
  24
  25#include <asm/io.h>
  26#include <asm/irq.h>
  27#include <asm/fs_pd.h>
  28#include <asm/prom.h>
  29
  30#include <linux/serial_core.h>
  31#include <linux/kernel.h>
  32
  33#include "cpm_uart.h"
  34
  35/**************************************************************/
  36
  37void cpm_line_cr_cmd(struct uart_cpm_port *port, int cmd)
  38{
  39        cpm_command(port->command, cmd);
  40}
  41
  42void __iomem *cpm_uart_map_pram(struct uart_cpm_port *port,
  43                                struct device_node *np)
  44{
  45        void __iomem *pram;
  46        unsigned long offset;
  47        struct resource res;
  48        resource_size_t len;
  49
  50        /* Don't remap parameter RAM if it has already been initialized
  51         * during console setup.
  52         */
  53        if (IS_SMC(port) && port->smcup)
  54                return port->smcup;
  55        else if (!IS_SMC(port) && port->sccup)
  56                return port->sccup;
  57
  58        if (of_address_to_resource(np, 1, &res))
  59                return NULL;
  60
  61        len = resource_size(&res);
  62        pram = ioremap(res.start, len);
  63        if (!pram)
  64                return NULL;
  65
  66        if (!IS_SMC(port))
  67                return pram;
  68
  69        if (len != 2) {
  70                printk(KERN_WARNING "cpm_uart[%d]: device tree references "
  71                        "SMC pram, using boot loader/wrapper pram mapping. "
  72                        "Please fix your device tree to reference the pram "
  73                        "base register instead.\n",
  74                        port->port.line);
  75                return pram;
  76        }
  77
  78        offset = cpm_dpalloc(PROFF_SMC_SIZE, 64);
  79        out_be16(pram, offset);
  80        iounmap(pram);
  81        return cpm_muram_addr(offset);
  82}
  83
  84void cpm_uart_unmap_pram(struct uart_cpm_port *port, void __iomem *pram)
  85{
  86        if (!IS_SMC(port))
  87                iounmap(pram);
  88}
  89
  90/*
  91 * Allocate DP-Ram and memory buffers. We need to allocate a transmit and
  92 * receive buffer descriptors from dual port ram, and a character
  93 * buffer area from host mem. If we are allocating for the console we need
  94 * to do it from bootmem
  95 */
  96int cpm_uart_allocbuf(struct uart_cpm_port *pinfo, unsigned int is_con)
  97{
  98        int dpmemsz, memsz;
  99        u8 __iomem *dp_mem;
 100        unsigned long dp_offset;
 101        u8 *mem_addr;
 102        dma_addr_t dma_addr = 0;
 103
 104        pr_debug("CPM uart[%d]:allocbuf\n", pinfo->port.line);
 105
 106        dpmemsz = sizeof(cbd_t) * (pinfo->rx_nrfifos + pinfo->tx_nrfifos);
 107        dp_offset = cpm_dpalloc(dpmemsz, 8);
 108        if (IS_ERR_VALUE(dp_offset)) {
 109                printk(KERN_ERR
 110                       "cpm_uart_cpm.c: could not allocate buffer descriptors\n");
 111                return -ENOMEM;
 112        }
 113
 114        dp_mem = cpm_dpram_addr(dp_offset);
 115
 116        memsz = L1_CACHE_ALIGN(pinfo->rx_nrfifos * pinfo->rx_fifosize) +
 117            L1_CACHE_ALIGN(pinfo->tx_nrfifos * pinfo->tx_fifosize);
 118        if (is_con) {
 119                mem_addr = kzalloc(memsz, GFP_NOWAIT);
 120                dma_addr = virt_to_bus(mem_addr);
 121        }
 122        else
 123                mem_addr = dma_alloc_coherent(pinfo->port.dev, memsz, &dma_addr,
 124                                              GFP_KERNEL);
 125
 126        if (mem_addr == NULL) {
 127                cpm_dpfree(dp_offset);
 128                printk(KERN_ERR
 129                       "cpm_uart_cpm.c: could not allocate coherent memory\n");
 130                return -ENOMEM;
 131        }
 132
 133        pinfo->dp_addr = dp_offset;
 134        pinfo->mem_addr = mem_addr;
 135        pinfo->dma_addr = dma_addr;
 136        pinfo->mem_size = memsz;
 137
 138        pinfo->rx_buf = mem_addr;
 139        pinfo->tx_buf = pinfo->rx_buf + L1_CACHE_ALIGN(pinfo->rx_nrfifos
 140                                                       * pinfo->rx_fifosize);
 141
 142        pinfo->rx_bd_base = (cbd_t __iomem *)dp_mem;
 143        pinfo->tx_bd_base = pinfo->rx_bd_base + pinfo->rx_nrfifos;
 144
 145        return 0;
 146}
 147
 148void cpm_uart_freebuf(struct uart_cpm_port *pinfo)
 149{
 150        dma_free_coherent(pinfo->port.dev, L1_CACHE_ALIGN(pinfo->rx_nrfifos *
 151                                                          pinfo->rx_fifosize) +
 152                          L1_CACHE_ALIGN(pinfo->tx_nrfifos *
 153                                         pinfo->tx_fifosize), (void __force *)pinfo->mem_addr,
 154                          pinfo->dma_addr);
 155
 156        cpm_dpfree(pinfo->dp_addr);
 157}
 158