drivers/tty/serial/cpm_uart/cpm_uart_cpm2.c

   1 /*
   2  *  linux/drivers/serial/cpm_uart_cpm2.c
   3  *
   4  *  Driver for CPM (SCC/SMC) serial ports; CPM2 definitions
   5  *
   6  *  Maintainer: Kumar Gala (galak@kernel.crashing.org) (CPM2)
   7  *              Pantelis Antoniou (panto@intracom.gr) (CPM1)
   8  *
   9  *  Copyright (C) 2004 Freescale Semiconductor, Inc.
  10  *            (C) 2004 Intracom, S.A.
  11  *            (C) 2006 MontaVista Software, Inc.
  12  *              Vitaly Bordug <vbordug@ru.mvista.com>
  13  *
  14  * This program is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * This program is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with this program; if not, write to the Free Software
  26  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  27  *
  28  */
  29
  30 #include <linux/module.h>
  31 #include <linux/tty.h>
  32 #include <linux/ioport.h>
  33 #include <linux/slab.h>
  34 #include <linux/init.h>
  35 #include <linux/serial.h>
  36 #include <linux/console.h>
  37 #include <linux/sysrq.h>
  38 #include <linux/device.h>
  39 #include <linux/bootmem.h>
  40 #include <linux/dma-mapping.h>
  41
  42 #include <asm/io.h>
  43 #include <asm/irq.h>
  44 #include <asm/fs_pd.h>
  45 #include <asm/prom.h>
  46
  47 #include <linux/serial_core.h>
  48 #include <linux/kernel.h>
  49
  50 #include "cpm_uart.h"
  51
  52 /**************************************************************/
  53
  54 void cpm_line_cr_cmd(struct uart_cpm_port *port, int cmd)
  55 {
  56         cpm_command(port->command, cmd);
  57 }
  58
  59 void __iomem *cpm_uart_map_pram(struct uart_cpm_port *port,
  60                                 struct device_node *np)
  61 {
  62         void __iomem *pram;
  63         unsigned long offset;
  64         struct resource res;
  65         resource_size_t len;
  66
  67         /* Don't remap parameter RAM if it has already been initialized
  68          * during console setup.
  69          */
  70         if (IS_SMC(port) && port->smcup)
  71                 return port->smcup;
  72         else if (!IS_SMC(port) && port->sccup)
  73                 return port->sccup;
  74
  75         if (of_address_to_resource(np, 1, &res))
  76                 return NULL;
  77
  78         len = resource_size(&res);
  79         pram = ioremap(res.start, len);
  80         if (!pram)
  81                 return NULL;
  82
  83         if (!IS_SMC(port))
  84                 return pram;
  85
  86         if (len != 2) {
  87                 printk(KERN_WARNING "cpm_uart[%d]: device tree references "
  88                         "SMC pram, using boot loader/wrapper pram mapping. "
  89                         "Please fix your device tree to reference the pram "
  90                         "base register instead.\n",
  91                         port->port.line);
  92                 return pram;
  93         }
  94
  95         offset = cpm_dpalloc(PROFF_SMC_SIZE, 64);
  96         out_be16(pram, offset);
  97         iounmap(pram);
  98         return cpm_muram_addr(offset);
  99 }
 100
 101 void cpm_uart_unmap_pram(struct uart_cpm_port *port, void __iomem *pram)
 102 {
 103         if (!IS_SMC(port))
 104                 iounmap(pram);
 105 }
 106
 107 /*
 108  * Allocate DP-Ram and memory buffers. We need to allocate a transmit and
 109  * receive buffer descriptors from dual port ram, and a character
 110  * buffer area from host mem. If we are allocating for the console we need
 111  * to do it from bootmem
 112  */
 113 int cpm_uart_allocbuf(struct uart_cpm_port *pinfo, unsigned int is_con)
 114 {
 115         int dpmemsz, memsz;
 116         u8 __iomem *dp_mem;
 117         unsigned long dp_offset;
 118         u8 *mem_addr;
 119         dma_addr_t dma_addr = 0;
 120
 121         pr_debug("CPM uart[%d]:allocbuf\n", pinfo->port.line);
 122
 123         dpmemsz = sizeof(cbd_t) * (pinfo->rx_nrfifos + pinfo->tx_nrfifos);
 124         dp_offset = cpm_dpalloc(dpmemsz, 8);
 125         if (IS_ERR_VALUE(dp_offset)) {
 126                 printk(KERN_ERR
 127                        "cpm_uart_cpm.c: could not allocate buffer descriptors\n");
 128                 return -ENOMEM;
 129         }
 130
 131         dp_mem = cpm_dpram_addr(dp_offset);
 132
 133         memsz = L1_CACHE_ALIGN(pinfo->rx_nrfifos * pinfo->rx_fifosize) +
 134             L1_CACHE_ALIGN(pinfo->tx_nrfifos * pinfo->tx_fifosize);
 135         if (is_con) {
 136                 mem_addr = kzalloc(memsz, GFP_NOWAIT);
 137                 dma_addr = virt_to_bus(mem_addr);
 138         }
 139         else
 140                 mem_addr = dma_alloc_coherent(pinfo->port.dev, memsz, &dma_addr,
 141                                               GFP_KERNEL);
 142
 143         if (mem_addr == NULL) {
 144                 cpm_dpfree(dp_offset);
 145                 printk(KERN_ERR
 146                        "cpm_uart_cpm.c: could not allocate coherent memory\n");
 147                 return -ENOMEM;
 148         }
 149
 150         pinfo->dp_addr = dp_offset;
 151         pinfo->mem_addr = mem_addr;
 152         pinfo->dma_addr = dma_addr;
 153         pinfo->mem_size = memsz;
 154
 155         pinfo->rx_buf = mem_addr;
 156         pinfo->tx_buf = pinfo->rx_buf + L1_CACHE_ALIGN(pinfo->rx_nrfifos
 157                                                        * pinfo->rx_fifosize);
 158
 159         pinfo->rx_bd_base = (cbd_t __iomem *)dp_mem;
 160         pinfo->tx_bd_base = pinfo->rx_bd_base + pinfo->rx_nrfifos;
 161
 162         return 0;
 163 }
 164
 165 void cpm_uart_freebuf(struct uart_cpm_port *pinfo)
 166 {
 167         dma_free_coherent(pinfo->port.dev, L1_CACHE_ALIGN(pinfo->rx_nrfifos *
 168                                                           pinfo->rx_fifosize) +
 169                           L1_CACHE_ALIGN(pinfo->tx_nrfifos *
 170                                          pinfo->tx_fifosize), (void __force *)pinfo->mem_addr,
 171                           pinfo->dma_addr);
 172
 173         cpm_dpfree(pinfo->dp_addr);
 174 }