imx-audmux.c

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/*
 * Copyright 2012 Freescale Semiconductor, Inc.
 * Copyright 2012 Linaro Ltd.
 * Copyright 2009 Pengutronix, Sascha Hauer <[email protected]>
 *
 * Initial development of this code was funded by
 * Phytec Messtechnik GmbH, http://www.phytec.de
 *
 * 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.
 */

#include <linux/clk.h>
#include <linux/debugfs.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/pinctrl/consumer.h>

#include "imx-audmux.h"

#define DRIVER_NAME "imx-audmux"

static struct clk *audmux_clk;
static void __iomem *audmux_base;

#define IMX_AUDMUX_V2_PTCR(x)       ((x) * 8)
#define IMX_AUDMUX_V2_PDCR(x)       ((x) * 8 + 4)

#ifdef CONFIG_DEBUG_FS
static struct dentry *audmux_debugfs_root;

/* There is an annoying discontinuity in the SSI numbering with regard
 * to the Linux number of the devices */
static const char *audmux_port_string(int port)
{
    switch (port) {
    case MX31_AUDMUX_PORT1_SSI0:
        return "imx-ssi.0";
    case MX31_AUDMUX_PORT2_SSI1:
        return "imx-ssi.1";
    case MX31_AUDMUX_PORT3_SSI_PINS_3:
        return "SSI3";
    case MX31_AUDMUX_PORT4_SSI_PINS_4:
        return "SSI4";
    case MX31_AUDMUX_PORT5_SSI_PINS_5:
        return "SSI5";
    case MX31_AUDMUX_PORT6_SSI_PINS_6:
        return "SSI6";
    default:
        return "UNKNOWN";
    }
}

static ssize_t audmux_read_file(struct file *file, char __user *user_buf,
                size_t count, loff_t *ppos)
{
    ssize_t ret;
    char *buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
    int port = (int)file->private_data;
    u32 pdcr, ptcr;

    if (!buf)
        return -ENOMEM;

    if (audmux_clk)
        clk_prepare_enable(audmux_clk);

    ptcr = readl(audmux_base + IMX_AUDMUX_V2_PTCR(port));
    pdcr = readl(audmux_base + IMX_AUDMUX_V2_PDCR(port));

    if (audmux_clk)
        clk_disable_unprepare(audmux_clk);

    ret = snprintf(buf, PAGE_SIZE, "PDCR: %08x\nPTCR: %08x\n",
               pdcr, ptcr);

    if (ptcr & IMX_AUDMUX_V2_PTCR_TFSDIR)
        ret += snprintf(buf + ret, PAGE_SIZE - ret,
                "TxFS output from %s, ",
                audmux_port_string((ptcr >> 27) & 0x7));
    else
        ret += snprintf(buf + ret, PAGE_SIZE - ret,
                "TxFS input, ");

    if (ptcr & IMX_AUDMUX_V2_PTCR_TCLKDIR)
        ret += snprintf(buf + ret, PAGE_SIZE - ret,
                "TxClk output from %s",
                audmux_port_string((ptcr >> 22) & 0x7));
    else
        ret += snprintf(buf + ret, PAGE_SIZE - ret,
                "TxClk input");

    ret += snprintf(buf + ret, PAGE_SIZE - ret, "\n");

    if (ptcr & IMX_AUDMUX_V2_PTCR_SYN) {
        ret += snprintf(buf + ret, PAGE_SIZE - ret,
                "Port is symmetric");
    } else {
        if (ptcr & IMX_AUDMUX_V2_PTCR_RFSDIR)
            ret += snprintf(buf + ret, PAGE_SIZE - ret,
                    "RxFS output from %s, ",
                    audmux_port_string((ptcr >> 17) & 0x7));
        else
            ret += snprintf(buf + ret, PAGE_SIZE - ret,
                    "RxFS input, ");

        if (ptcr & IMX_AUDMUX_V2_PTCR_RCLKDIR)
            ret += snprintf(buf + ret, PAGE_SIZE - ret,
                    "RxClk output from %s",
                    audmux_port_string((ptcr >> 12) & 0x7));
        else
            ret += snprintf(buf + ret, PAGE_SIZE - ret,
                    "RxClk input");
    }

    ret += snprintf(buf + ret, PAGE_SIZE - ret,
            "\nData received from %s\n",
            audmux_port_string((pdcr >> 13) & 0x7));

    ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);

    kfree(buf);

    return ret;
}

static const struct file_operations audmux_debugfs_fops = {
    .open = simple_open,
    .read = audmux_read_file,
    .llseek = default_llseek,
};

static void __init audmux_debugfs_init(void)
{
    int i;
    char buf[20];

    audmux_debugfs_root = debugfs_create_dir("audmux", NULL);
    if (!audmux_debugfs_root) {
        pr_warning("Failed to create AUDMUX debugfs root\n");
        return;
    }

    for (i = 0; i < MX31_AUDMUX_PORT7_SSI_PINS_7 + 1; i++) {
        snprintf(buf, sizeof(buf), "ssi%d", i);
        if (!debugfs_create_file(buf, 0444, audmux_debugfs_root,
                     (void *)i, &audmux_debugfs_fops))
            pr_warning("Failed to create AUDMUX port %d debugfs file\n",
                   i);
    }
}

static void __devexit audmux_debugfs_remove(void)
{
    debugfs_remove_recursive(audmux_debugfs_root);
}
#else
static inline void audmux_debugfs_init(void)
{
}

static inline void audmux_debugfs_remove(void)
{
}
#endif

enum imx_audmux_type {
    IMX21_AUDMUX,
    IMX31_AUDMUX,
} audmux_type;

static struct platform_device_id imx_audmux_ids[] = {
    {
        .name = "imx21-audmux",
        .driver_data = IMX21_AUDMUX,
    }, {
        .name = "imx31-audmux",
        .driver_data = IMX31_AUDMUX,
    }, {
        /* sentinel */
    }
};
MODULE_DEVICE_TABLE(platform, imx_audmux_ids);

static const struct of_device_id imx_audmux_dt_ids[] = {
    { .compatible = "fsl,imx21-audmux", .data = &imx_audmux_ids[0], },
    { .compatible = "fsl,imx31-audmux", .data = &imx_audmux_ids[1], },
    { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, imx_audmux_dt_ids);

static const uint8_t port_mapping[] = {
    0x0, 0x4, 0x8, 0x10, 0x14, 0x1c,
};

int imx_audmux_v1_configure_port(unsigned int port, unsigned int pcr)
{
    if (audmux_type != IMX21_AUDMUX)
        return -EINVAL;

    if (!audmux_base)
        return -ENOSYS;

    if (port >= ARRAY_SIZE(port_mapping))
        return -EINVAL;

    writel(pcr, audmux_base + port_mapping[port]);

    return 0;
}
EXPORT_SYMBOL_GPL(imx_audmux_v1_configure_port);

int imx_audmux_v2_configure_port(unsigned int port, unsigned int ptcr,
        unsigned int pdcr)
{
    if (audmux_type != IMX31_AUDMUX)
        return -EINVAL;

    if (!audmux_base)
        return -ENOSYS;

    if (audmux_clk)
        clk_prepare_enable(audmux_clk);

    writel(ptcr, audmux_base + IMX_AUDMUX_V2_PTCR(port));
    writel(pdcr, audmux_base + IMX_AUDMUX_V2_PDCR(port));

    if (audmux_clk)
        clk_disable_unprepare(audmux_clk);

    return 0;
}
EXPORT_SYMBOL_GPL(imx_audmux_v2_configure_port);

static int __devinit imx_audmux_probe(struct platform_device *pdev)
{
    struct resource *res;
    struct pinctrl *pinctrl;
    const struct of_device_id *of_id =
            of_match_device(imx_audmux_dt_ids, &pdev->dev);

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    audmux_base = devm_request_and_ioremap(&pdev->dev, res);
    if (!audmux_base)
        return -EADDRNOTAVAIL;

    pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
    if (IS_ERR(pinctrl)) {
        dev_err(&pdev->dev, "setup pinctrl failed!");
        return PTR_ERR(pinctrl);
    }

    audmux_clk = clk_get(&pdev->dev, "audmux");
    if (IS_ERR(audmux_clk)) {
        dev_dbg(&pdev->dev, "cannot get clock: %ld\n",
                PTR_ERR(audmux_clk));
        audmux_clk = NULL;
    }

    if (of_id)
        pdev->id_entry = of_id->data;
    audmux_type = pdev->id_entry->driver_data;
    if (audmux_type == IMX31_AUDMUX)
        audmux_debugfs_init();

    return 0;
}

static int __devexit imx_audmux_remove(struct platform_device *pdev)
{
    if (audmux_type == IMX31_AUDMUX)
        audmux_debugfs_remove();
    clk_put(audmux_clk);

    return 0;
}

static struct platform_driver imx_audmux_driver = {
    .probe      = imx_audmux_probe,
    .remove     = __devexit_p(imx_audmux_remove),
    .id_table   = imx_audmux_ids,
    .driver = {
        .name   = DRIVER_NAME,
        .owner  = THIS_MODULE,
        .of_match_table = imx_audmux_dt_ids,
    }
};

static int __init imx_audmux_init(void)
{
    return platform_driver_register(&imx_audmux_driver);
}
subsys_initcall(imx_audmux_init);

static void __exit imx_audmux_exit(void)
{
    platform_driver_unregister(&imx_audmux_driver);
}
module_exit(imx_audmux_exit);

MODULE_DESCRIPTION("Freescale i.MX AUDMUX driver");
MODULE_AUTHOR("Sascha Hauer <[email protected]>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:" DRIVER_NAME);