cpm_uart_cpm2.c

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/*
 *  Driver for CPM (SCC/SMC) serial ports; CPM2 definitions
 *
 *  Maintainer: Kumar Gala ([email protected]) (CPM2)
 *              Pantelis Antoniou ([email protected]) (CPM1)
 *
 *  Copyright (C) 2004 Freescale Semiconductor, Inc.
 *            (C) 2004 Intracom, S.A.
 *            (C) 2006 MontaVista Software, Inc.
 *      Vitaly Bordug <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include <linux/module.h>
#include <linux/tty.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/serial.h>
#include <linux/console.h>
#include <linux/sysrq.h>
#include <linux/device.h>
#include <linux/bootmem.h>
#include <linux/dma-mapping.h>

#include <asm/io.h>
#include <asm/irq.h>
#include <asm/fs_pd.h>
#include <asm/prom.h>

#include <linux/serial_core.h>
#include <linux/kernel.h>

#include "cpm_uart.h"

/**************************************************************/

void cpm_line_cr_cmd(struct uart_cpm_port *port, int cmd)
{
    cpm_command(port->command, cmd);
}

void __iomem *cpm_uart_map_pram(struct uart_cpm_port *port,
                struct device_node *np)
{
    void __iomem *pram;
    unsigned long offset;
    struct resource res;
    resource_size_t len;

    /* Don't remap parameter RAM if it has already been initialized
     * during console setup.
     */
    if (IS_SMC(port) && port->smcup)
        return port->smcup;
    else if (!IS_SMC(port) && port->sccup)
        return port->sccup;

    if (of_address_to_resource(np, 1, &res))
        return NULL;

    len = resource_size(&res);
    pram = ioremap(res.start, len);
    if (!pram)
        return NULL;

    if (!IS_SMC(port))
        return pram;

    if (len != 2) {
        printk(KERN_WARNING "cpm_uart[%d]: device tree references "
            "SMC pram, using boot loader/wrapper pram mapping. "
            "Please fix your device tree to reference the pram "
            "base register instead.\n",
            port->port.line);
        return pram;
    }

    offset = cpm_dpalloc(PROFF_SMC_SIZE, 64);
    out_be16(pram, offset);
    iounmap(pram);
    return cpm_muram_addr(offset);
}

void cpm_uart_unmap_pram(struct uart_cpm_port *port, void __iomem *pram)
{
    if (!IS_SMC(port))
        iounmap(pram);
}

/*
 * Allocate DP-Ram and memory buffers. We need to allocate a transmit and
 * receive buffer descriptors from dual port ram, and a character
 * buffer area from host mem. If we are allocating for the console we need
 * to do it from bootmem
 */
int cpm_uart_allocbuf(struct uart_cpm_port *pinfo, unsigned int is_con)
{
    int dpmemsz, memsz;
    u8 __iomem *dp_mem;
    unsigned long dp_offset;
    u8 *mem_addr;
    dma_addr_t dma_addr = 0;

    pr_debug("CPM uart[%d]:allocbuf\n", pinfo->port.line);

    dpmemsz = sizeof(cbd_t) * (pinfo->rx_nrfifos + pinfo->tx_nrfifos);
    dp_offset = cpm_dpalloc(dpmemsz, 8);
    if (IS_ERR_VALUE(dp_offset)) {
        printk(KERN_ERR
               "cpm_uart_cpm.c: could not allocate buffer descriptors\n");
        return -ENOMEM;
    }

    dp_mem = cpm_dpram_addr(dp_offset);

    memsz = L1_CACHE_ALIGN(pinfo->rx_nrfifos * pinfo->rx_fifosize) +
        L1_CACHE_ALIGN(pinfo->tx_nrfifos * pinfo->tx_fifosize);
    if (is_con) {
        mem_addr = kzalloc(memsz, GFP_NOWAIT);
        dma_addr = virt_to_bus(mem_addr);
    }
    else
        mem_addr = dma_alloc_coherent(pinfo->port.dev, memsz, &dma_addr,
                          GFP_KERNEL);

    if (mem_addr == NULL) {
        cpm_dpfree(dp_offset);
        printk(KERN_ERR
               "cpm_uart_cpm.c: could not allocate coherent memory\n");
        return -ENOMEM;
    }

    pinfo->dp_addr = dp_offset;
    pinfo->mem_addr = mem_addr;
    pinfo->dma_addr = dma_addr;
    pinfo->mem_size = memsz;

    pinfo->rx_buf = mem_addr;
    pinfo->tx_buf = pinfo->rx_buf + L1_CACHE_ALIGN(pinfo->rx_nrfifos
                               * pinfo->rx_fifosize);

    pinfo->rx_bd_base = (cbd_t __iomem *)dp_mem;
    pinfo->tx_bd_base = pinfo->rx_bd_base + pinfo->rx_nrfifos;

    return 0;
}

void cpm_uart_freebuf(struct uart_cpm_port *pinfo)
{
    dma_free_coherent(pinfo->port.dev, L1_CACHE_ALIGN(pinfo->rx_nrfifos *
                              pinfo->rx_fifosize) +
              L1_CACHE_ALIGN(pinfo->tx_nrfifos *
                     pinfo->tx_fifosize), (void __force *)pinfo->mem_addr,
              pinfo->dma_addr);

    cpm_dpfree(pinfo->dp_addr);
}