drivers/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/init.h>
  34 #include <linux/serial.h>
  35 #include <linux/console.h>
  36 #include <linux/sysrq.h>
  37 #include <linux/device.h>
  38 #include <linux/bootmem.h>
  39 #include <linux/dma-mapping.h>
  40
  41 #include <asm/io.h>
  42 #include <asm/irq.h>
  43 #include <asm/fs_pd.h>
  44 #include <asm/prom.h>
  45
  46 #include <linux/serial_core.h>
  47 #include <linux/kernel.h>
  48
  49 #include "cpm_uart.h"
  50
  51 /**************************************************************/
  52
  53 void cpm_line_cr_cmd(struct uart_cpm_port *port, int cmd)
  54 {
  55         cpm_command(port->command, cmd);
  56 }
  57
  58 void __iomem *cpm_uart_map_pram(struct uart_cpm_port *port,
  59                                 struct device_node *np)
  60 {
  61         void __iomem *pram;
  62         unsigned long offset;
  63         struct resource res;
  64         unsigned long len;
  65
  66         /* Don't remap parameter RAM if it has already been initialized
  67          * during console setup.
  68          */
  69         if (IS_SMC(port) && port->smcup)
  70                 return port->smcup;
  71         else if (!IS_SMC(port) && port->sccup)
  72                 return port->sccup;
  73
  74         if (of_address_to_resource(np, 1, &res))
  75                 return NULL;
  76
  77         len = 1 + res.end - res.start;
  78         pram = ioremap(res.start, len);
  79         if (!pram)
  80                 return NULL;
  81
  82         if (!IS_SMC(port))
  83                 return pram;
  84
  85         if (len != 2) {
  86                 printk(KERN_WARNING "cpm_uart[%d]: device tree references "
  87                         "SMC pram, using boot loader/wrapper pram mapping. "
  88                         "Please fix your device tree to reference the pram "
  89                         "base register instead.\n",
  90                         port->port.line);
  91                 return pram;
  92         }
  93
  94         offset = cpm_dpalloc(PROFF_SMC_SIZE, 64);
  95         out_be16(pram, offset);
  96         iounmap(pram);
  97         return cpm_muram_addr(offset);
  98 }
  99
 100 void cpm_uart_unmap_pram(struct uart_cpm_port *port, void __iomem *pram)
 101 {
 102         if (!IS_SMC(port))
 103                 iounmap(pram);
 104 }
 105
 106 /*
 107  * Allocate DP-Ram and memory buffers. We need to allocate a transmit and
 108  * receive buffer descriptors from dual port ram, and a character
 109  * buffer area from host mem. If we are allocating for the console we need
 110  * to do it from bootmem
 111  */
 112 int cpm_uart_allocbuf(struct uart_cpm_port *pinfo, unsigned int is_con)
 113 {
 114         int dpmemsz, memsz;
 115         u8 __iomem *dp_mem;
 116         unsigned long dp_offset;
 117         u8 *mem_addr;
 118         dma_addr_t dma_addr = 0;
 119
 120         pr_debug("CPM uart[%d]:allocbuf\n", pinfo->port.line);
 121
 122         dpmemsz = sizeof(cbd_t) * (pinfo->rx_nrfifos + pinfo->tx_nrfifos);
 123         dp_offset = cpm_dpalloc(dpmemsz, 8);
 124         if (IS_ERR_VALUE(dp_offset)) {
 125                 printk(KERN_ERR
 126                        "cpm_uart_cpm.c: could not allocate buffer descriptors\n");
 127                 return -ENOMEM;
 128         }
 129
 130         dp_mem = cpm_dpram_addr(dp_offset);
 131
 132         memsz = L1_CACHE_ALIGN(pinfo->rx_nrfifos * pinfo->rx_fifosize) +
 133             L1_CACHE_ALIGN(pinfo->tx_nrfifos * pinfo->tx_fifosize);
 134         if (is_con) {
 135                 mem_addr = kzalloc(memsz, GFP_NOWAIT);
 136                 dma_addr = virt_to_bus(mem_addr);
 137         }
 138         else
 139                 mem_addr = dma_alloc_coherent(pinfo->port.dev, memsz, &dma_addr,
 140                                               GFP_KERNEL);
 141
 142         if (mem_addr == NULL) {
 143                 cpm_dpfree(dp_offset);
 144                 printk(KERN_ERR
 145                        "cpm_uart_cpm.c: could not allocate coherent memory\n");
 146                 return -ENOMEM;
 147         }
 148
 149         pinfo->dp_addr = dp_offset;
 150         pinfo->mem_addr = mem_addr;
 151         pinfo->dma_addr = dma_addr;
 152         pinfo->mem_size = memsz;
 153
 154         pinfo->rx_buf = mem_addr;
 155         pinfo->tx_buf = pinfo->rx_buf + L1_CACHE_ALIGN(pinfo->rx_nrfifos
 156                                                        * pinfo->rx_fifosize);
 157
 158         pinfo->rx_bd_base = (cbd_t __iomem *)dp_mem;
 159         pinfo->tx_bd_base = pinfo->rx_bd_base + pinfo->rx_nrfifos;
 160
 161         return 0;
 162 }
 163
 164 void cpm_uart_freebuf(struct uart_cpm_port *pinfo)
 165 {
 166         dma_free_coherent(pinfo->port.dev, L1_CACHE_ALIGN(pinfo->rx_nrfifos *
 167                                                           pinfo->rx_fifosize) +
 168                           L1_CACHE_ALIGN(pinfo->tx_nrfifos *
 169                                          pinfo->tx_fifosize), (void __force *)pinfo->mem_addr,
 170                           pinfo->dma_addr);
 171
 172         cpm_dpfree(pinfo->dp_addr);
 173 }