dma.c

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/* linux/arch/arm/mach-msm/dma.c
 *
 * Copyright (C) 2007 Google, Inc.
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * 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.
 *
 */

#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/interrupt.h>
#include <linux/completion.h>
#include <mach/dma.h>

#define MSM_DMOV_CHANNEL_COUNT 16

enum {
    MSM_DMOV_PRINT_ERRORS = 1,
    MSM_DMOV_PRINT_IO = 2,
    MSM_DMOV_PRINT_FLOW = 4
};

static DEFINE_SPINLOCK(msm_dmov_lock);
static struct clk *msm_dmov_clk;
static unsigned int channel_active;
static struct list_head ready_commands[MSM_DMOV_CHANNEL_COUNT];
static struct list_head active_commands[MSM_DMOV_CHANNEL_COUNT];
unsigned int msm_dmov_print_mask = MSM_DMOV_PRINT_ERRORS;

#define MSM_DMOV_DPRINTF(mask, format, args...) \
    do { \
        if ((mask) & msm_dmov_print_mask) \
            printk(KERN_ERR format, args); \
    } while (0)
#define PRINT_ERROR(format, args...) \
    MSM_DMOV_DPRINTF(MSM_DMOV_PRINT_ERRORS, format, args);
#define PRINT_IO(format, args...) \
    MSM_DMOV_DPRINTF(MSM_DMOV_PRINT_IO, format, args);
#define PRINT_FLOW(format, args...) \
    MSM_DMOV_DPRINTF(MSM_DMOV_PRINT_FLOW, format, args);

void msm_dmov_stop_cmd(unsigned id, struct msm_dmov_cmd *cmd, int graceful)
{
    writel((graceful << 31), DMOV_FLUSH0(id));
}

void msm_dmov_enqueue_cmd(unsigned id, struct msm_dmov_cmd *cmd)
{
    unsigned long irq_flags;
    unsigned int status;

    spin_lock_irqsave(&msm_dmov_lock, irq_flags);
    if (!channel_active)
        clk_enable(msm_dmov_clk);
    dsb();
    status = readl(DMOV_STATUS(id));
    if (list_empty(&ready_commands[id]) &&
        (status & DMOV_STATUS_CMD_PTR_RDY)) {
#if 0
        if (list_empty(&active_commands[id])) {
            PRINT_FLOW("msm_dmov_enqueue_cmd(%d), enable interrupt\n", id);
            writel(DMOV_CONFIG_IRQ_EN, DMOV_CONFIG(id));
        }
#endif
        if (cmd->execute_func)
            cmd->execute_func(cmd);
        PRINT_IO("msm_dmov_enqueue_cmd(%d), start command, status %x\n", id, status);
        list_add_tail(&cmd->list, &active_commands[id]);
        if (!channel_active)
            enable_irq(INT_ADM_AARM);
        channel_active |= 1U << id;
        writel(cmd->cmdptr, DMOV_CMD_PTR(id));
    } else {
        if (!channel_active)
            clk_disable(msm_dmov_clk);
        if (list_empty(&active_commands[id]))
            PRINT_ERROR("msm_dmov_enqueue_cmd(%d), error datamover stalled, status %x\n", id, status);

        PRINT_IO("msm_dmov_enqueue_cmd(%d), enqueue command, status %x\n", id, status);
        list_add_tail(&cmd->list, &ready_commands[id]);
    }
    spin_unlock_irqrestore(&msm_dmov_lock, irq_flags);
}

struct msm_dmov_exec_cmdptr_cmd {
    struct msm_dmov_cmd dmov_cmd;
    struct completion complete;
    unsigned id;
    unsigned int result;
    struct msm_dmov_errdata err;
};

static void
dmov_exec_cmdptr_complete_func(struct msm_dmov_cmd *_cmd,
                   unsigned int result,
                   struct msm_dmov_errdata *err)
{
    struct msm_dmov_exec_cmdptr_cmd *cmd = container_of(_cmd, struct msm_dmov_exec_cmdptr_cmd, dmov_cmd);
    cmd->result = result;
    if (result != 0x80000002 && err)
        memcpy(&cmd->err, err, sizeof(struct msm_dmov_errdata));

    complete(&cmd->complete);
}

int msm_dmov_exec_cmd(unsigned id, unsigned int cmdptr)
{
    struct msm_dmov_exec_cmdptr_cmd cmd;

    PRINT_FLOW("dmov_exec_cmdptr(%d, %x)\n", id, cmdptr);

    cmd.dmov_cmd.cmdptr = cmdptr;
    cmd.dmov_cmd.complete_func = dmov_exec_cmdptr_complete_func;
    cmd.dmov_cmd.execute_func = NULL;
    cmd.id = id;
    init_completion(&cmd.complete);

    msm_dmov_enqueue_cmd(id, &cmd.dmov_cmd);
    wait_for_completion(&cmd.complete);

    if (cmd.result != 0x80000002) {
        PRINT_ERROR("dmov_exec_cmdptr(%d): ERROR, result: %x\n", id, cmd.result);
        PRINT_ERROR("dmov_exec_cmdptr(%d):  flush: %x %x %x %x\n",
            id, cmd.err.flush[0], cmd.err.flush[1], cmd.err.flush[2], cmd.err.flush[3]);
        return -EIO;
    }
    PRINT_FLOW("dmov_exec_cmdptr(%d, %x) done\n", id, cmdptr);
    return 0;
}


static irqreturn_t msm_datamover_irq_handler(int irq, void *dev_id)
{
    unsigned int int_status, mask, id;
    unsigned long irq_flags;
    unsigned int ch_status;
    unsigned int ch_result;
    struct msm_dmov_cmd *cmd;

    spin_lock_irqsave(&msm_dmov_lock, irq_flags);

    int_status = readl(DMOV_ISR); /* read and clear interrupt */
    PRINT_FLOW("msm_datamover_irq_handler: DMOV_ISR %x\n", int_status);

    while (int_status) {
        mask = int_status & -int_status;
        id = fls(mask) - 1;
        PRINT_FLOW("msm_datamover_irq_handler %08x %08x id %d\n", int_status, mask, id);
        int_status &= ~mask;
        ch_status = readl(DMOV_STATUS(id));
        if (!(ch_status & DMOV_STATUS_RSLT_VALID)) {
            PRINT_FLOW("msm_datamover_irq_handler id %d, result not valid %x\n", id, ch_status);
            continue;
        }
        do {
            ch_result = readl(DMOV_RSLT(id));
            if (list_empty(&active_commands[id])) {
                PRINT_ERROR("msm_datamover_irq_handler id %d, got result "
                    "with no active command, status %x, result %x\n",
                    id, ch_status, ch_result);
                cmd = NULL;
            } else
                cmd = list_entry(active_commands[id].next, typeof(*cmd), list);
            PRINT_FLOW("msm_datamover_irq_handler id %d, status %x, result %x\n", id, ch_status, ch_result);
            if (ch_result & DMOV_RSLT_DONE) {
                PRINT_FLOW("msm_datamover_irq_handler id %d, status %x\n",
                    id, ch_status);
                PRINT_IO("msm_datamover_irq_handler id %d, got result "
                    "for %p, result %x\n", id, cmd, ch_result);
                if (cmd) {
                    list_del(&cmd->list);
                    dsb();
                    cmd->complete_func(cmd, ch_result, NULL);
                }
            }
            if (ch_result & DMOV_RSLT_FLUSH) {
                struct msm_dmov_errdata errdata;

                errdata.flush[0] = readl(DMOV_FLUSH0(id));
                errdata.flush[1] = readl(DMOV_FLUSH1(id));
                errdata.flush[2] = readl(DMOV_FLUSH2(id));
                errdata.flush[3] = readl(DMOV_FLUSH3(id));
                errdata.flush[4] = readl(DMOV_FLUSH4(id));
                errdata.flush[5] = readl(DMOV_FLUSH5(id));
                PRINT_FLOW("msm_datamover_irq_handler id %d, status %x\n", id, ch_status);
                PRINT_FLOW("msm_datamover_irq_handler id %d, flush, result %x, flush0 %x\n", id, ch_result, errdata.flush[0]);
                if (cmd) {
                    list_del(&cmd->list);
                    dsb();
                    cmd->complete_func(cmd, ch_result, &errdata);
                }
            }
            if (ch_result & DMOV_RSLT_ERROR) {
                struct msm_dmov_errdata errdata;

                errdata.flush[0] = readl(DMOV_FLUSH0(id));
                errdata.flush[1] = readl(DMOV_FLUSH1(id));
                errdata.flush[2] = readl(DMOV_FLUSH2(id));
                errdata.flush[3] = readl(DMOV_FLUSH3(id));
                errdata.flush[4] = readl(DMOV_FLUSH4(id));
                errdata.flush[5] = readl(DMOV_FLUSH5(id));

                PRINT_ERROR("msm_datamover_irq_handler id %d, status %x\n", id, ch_status);
                PRINT_ERROR("msm_datamover_irq_handler id %d, error, result %x, flush0 %x\n", id, ch_result, errdata.flush[0]);
                if (cmd) {
                    list_del(&cmd->list);
                    dsb();
                    cmd->complete_func(cmd, ch_result, &errdata);
                }
                /* this does not seem to work, once we get an error */
                /* the datamover will no longer accept commands */
                writel(0, DMOV_FLUSH0(id));
            }
            ch_status = readl(DMOV_STATUS(id));
            PRINT_FLOW("msm_datamover_irq_handler id %d, status %x\n", id, ch_status);
            if ((ch_status & DMOV_STATUS_CMD_PTR_RDY) && !list_empty(&ready_commands[id])) {
                cmd = list_entry(ready_commands[id].next, typeof(*cmd), list);
                list_move_tail(&cmd->list, &active_commands[id]);
                if (cmd->execute_func)
                    cmd->execute_func(cmd);
                PRINT_FLOW("msm_datamover_irq_handler id %d, start command\n", id);
                writel(cmd->cmdptr, DMOV_CMD_PTR(id));
            }
        } while (ch_status & DMOV_STATUS_RSLT_VALID);
        if (list_empty(&active_commands[id]) && list_empty(&ready_commands[id]))
            channel_active &= ~(1U << id);
        PRINT_FLOW("msm_datamover_irq_handler id %d, status %x\n", id, ch_status);
    }

    if (!channel_active) {
        disable_irq_nosync(INT_ADM_AARM);
        clk_disable(msm_dmov_clk);
    }

    spin_unlock_irqrestore(&msm_dmov_lock, irq_flags);
    return IRQ_HANDLED;
}

static int __init msm_init_datamover(void)
{
    int i;
    int ret;
    struct clk *clk;

    for (i = 0; i < MSM_DMOV_CHANNEL_COUNT; i++) {
        INIT_LIST_HEAD(&ready_commands[i]);
        INIT_LIST_HEAD(&active_commands[i]);
        writel(DMOV_CONFIG_IRQ_EN | DMOV_CONFIG_FORCE_TOP_PTR_RSLT | DMOV_CONFIG_FORCE_FLUSH_RSLT, DMOV_CONFIG(i));
    }
    clk = clk_get(NULL, "adm_clk");
    if (IS_ERR(clk))
        return PTR_ERR(clk);
    msm_dmov_clk = clk;
    ret = request_irq(INT_ADM_AARM, msm_datamover_irq_handler, 0, "msmdatamover", NULL);
    if (ret)
        return ret;
    disable_irq(INT_ADM_AARM);
    return 0;
}

arch_initcall(msm_init_datamover);