drivers/tty/serial/cpm_uart/cpm_uart_cpm2.c

   1 /*
   2  *  Driver for CPM (SCC/SMC) serial ports; CPM2 definitions
   3  *
   4  *  Maintainer: Kumar Gala (galak@kernel.crashing.org) (CPM2)
   5  *              Pantelis Antoniou (panto@intracom.gr) (CPM1)
   6  *
   7  *  Copyright (C) 2004 Freescale Semiconductor, Inc.
   8  *            (C) 2004 Intracom, S.A.
   9  *            (C) 2006 MontaVista Software, Inc.
  10  *              Vitaly Bordug <vbordug@ru.mvista.com>
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  25  *
  26  */
  27
  28 #include <linux/module.h>
  29 #include <linux/tty.h>
  30 #include <linux/ioport.h>
  31 #include <linux/slab.h>
  32 #include <linux/serial.h>
  33 #include <linux/console.h>
  34 #include <linux/sysrq.h>
  35 #include <linux/device.h>
  36 #include <linux/bootmem.h>
  37 #include <linux/dma-mapping.h>
  38
  39 #include <asm/io.h>
  40 #include <asm/irq.h>
  41 #include <asm/fs_pd.h>
  42 #include <asm/prom.h>
  43
  44 #include <linux/serial_core.h>
  45 #include <linux/kernel.h>
  46
  47 #include "cpm_uart.h"
  48
  49 /**************************************************************/
  50
  51 void cpm_line_cr_cmd(struct uart_cpm_port *port, int cmd)
  52 {
  53         cpm_command(port->command, cmd);
  54 }
  55
  56 void __iomem *cpm_uart_map_pram(struct uart_cpm_port *port,
  57                                 struct device_node *np)
  58 {
  59         void __iomem *pram;
  60         unsigned long offset;
  61         struct resource res;
  62         resource_size_t len;
  63
  64         /* Don't remap parameter RAM if it has already been initialized
  65          * during console setup.
  66          */
  67         if (IS_SMC(port) && port->smcup)
  68                 return port->smcup;
  69         else if (!IS_SMC(port) && port->sccup)
  70                 return port->sccup;
  71
  72         if (of_address_to_resource(np, 1, &res))
  73                 return NULL;
  74
  75         len = resource_size(&res);
  76         pram = ioremap(res.start, len);
  77         if (!pram)
  78                 return NULL;
  79
  80         if (!IS_SMC(port))
  81                 return pram;
  82
  83         if (len != 2) {
  84                 printk(KERN_WARNING "cpm_uart[%d]: device tree references "
  85                         "SMC pram, using boot loader/wrapper pram mapping. "
  86                         "Please fix your device tree to reference the pram "
  87                         "base register instead.\n",
  88                         port->port.line);
  89                 return pram;
  90         }
  91
  92         offset = cpm_dpalloc(PROFF_SMC_SIZE, 64);
  93         out_be16(pram, offset);
  94         iounmap(pram);
  95         return cpm_muram_addr(offset);
  96 }
  97
  98 void cpm_uart_unmap_pram(struct uart_cpm_port *port, void __iomem *pram)
  99 {
 100         if (!IS_SMC(port))
 101                 iounmap(pram);
 102 }
 103
 104 /*
 105  * Allocate DP-Ram and memory buffers. We need to allocate a transmit and
 106  * receive buffer descriptors from dual port ram, and a character
 107  * buffer area from host mem. If we are allocating for the console we need
 108  * to do it from bootmem
 109  */
 110 int cpm_uart_allocbuf(struct uart_cpm_port *pinfo, unsigned int is_con)
 111 {
 112         int dpmemsz, memsz;
 113         u8 __iomem *dp_mem;
 114         unsigned long dp_offset;
 115         u8 *mem_addr;
 116         dma_addr_t dma_addr = 0;
 117
 118         pr_debug("CPM uart[%d]:allocbuf\n", pinfo->port.line);
 119
 120         dpmemsz = sizeof(cbd_t) * (pinfo->rx_nrfifos + pinfo->tx_nrfifos);
 121         dp_offset = cpm_dpalloc(dpmemsz, 8);
 122         if (IS_ERR_VALUE(dp_offset)) {
 123                 printk(KERN_ERR
 124                        "cpm_uart_cpm.c: could not allocate buffer descriptors\n");
 125                 return -ENOMEM;
 126         }
 127
 128         dp_mem = cpm_dpram_addr(dp_offset);
 129
 130         memsz = L1_CACHE_ALIGN(pinfo->rx_nrfifos * pinfo->rx_fifosize) +
 131             L1_CACHE_ALIGN(pinfo->tx_nrfifos * pinfo->tx_fifosize);
 132         if (is_con) {
 133                 mem_addr = kzalloc(memsz, GFP_NOWAIT);
 134                 dma_addr = virt_to_bus(mem_addr);
 135         }
 136         else
 137                 mem_addr = dma_alloc_coherent(pinfo->port.dev, memsz, &dma_addr,
 138                                               GFP_KERNEL);
 139
 140         if (mem_addr == NULL) {
 141                 cpm_dpfree(dp_offset);
 142                 printk(KERN_ERR
 143                        "cpm_uart_cpm.c: could not allocate coherent memory\n");
 144                 return -ENOMEM;
 145         }
 146
 147         pinfo->dp_addr = dp_offset;
 148         pinfo->mem_addr = mem_addr;
 149         pinfo->dma_addr = dma_addr;
 150         pinfo->mem_size = memsz;
 151
 152         pinfo->rx_buf = mem_addr;
 153         pinfo->tx_buf = pinfo->rx_buf + L1_CACHE_ALIGN(pinfo->rx_nrfifos
 154                                                        * pinfo->rx_fifosize);
 155
 156         pinfo->rx_bd_base = (cbd_t __iomem *)dp_mem;
 157         pinfo->tx_bd_base = pinfo->rx_bd_base + pinfo->rx_nrfifos;
 158
 159         return 0;
 160 }
 161
 162 void cpm_uart_freebuf(struct uart_cpm_port *pinfo)
 163 {
 164         dma_free_coherent(pinfo->port.dev, L1_CACHE_ALIGN(pinfo->rx_nrfifos *
 165                                                           pinfo->rx_fifosize) +
 166                           L1_CACHE_ALIGN(pinfo->tx_nrfifos *
 167                                          pinfo->tx_fifosize), (void __force *)pinfo->mem_addr,
 168                           pinfo->dma_addr);
 169
 170         cpm_dpfree(pinfo->dp_addr);
 171 }