drivers/tty/serial/cpm_uart/cpm_uart_cpm2.c

   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
  37 void cpm_line_cr_cmd(struct uart_cpm_port *port, int cmd)
  38 {
  39         cpm_command(port->command, cmd);
  40 }
  41
  42 void __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
  84 void 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  */
  96 int 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
 148 void 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 }