mfp-pxa2xx.c

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/*
 *  linux/arch/arm/mach-pxa/mfp-pxa2xx.c
 *
 *  PXA2xx pin mux configuration support
 *
 *  The GPIOs on PXA2xx can be configured as one of many alternate
 *  functions, this is by concept samilar to the MFP configuration
 *  on PXA3xx,  what's more important, the low power pin state and
 *  wakeup detection are also supported by the same framework.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 */
#include <linux/gpio.h>
#include <linux/gpio-pxa.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/syscore_ops.h>

#include <mach/pxa2xx-regs.h>
#include <mach/mfp-pxa2xx.h>

#include "generic.h"

#define PGSR(x)     __REG2(0x40F00020, (x) << 2)
#define __GAFR(u, x)    __REG2((u) ? 0x40E00058 : 0x40E00054, (x) << 3)
#define GAFR_L(x)   __GAFR(0, x)
#define GAFR_U(x)   __GAFR(1, x)

#define BANK_OFF(n) (((n) < 3) ? (n) << 2 : 0x100 + (((n) - 3) << 2))
#define GPLR(x)     __REG2(0x40E00000, BANK_OFF((x) >> 5))
#define GPDR(x)     __REG2(0x40E00000, BANK_OFF((x) >> 5) + 0x0c)
#define GPSR(x)     __REG2(0x40E00000, BANK_OFF((x) >> 5) + 0x18)
#define GPCR(x)     __REG2(0x40E00000, BANK_OFF((x) >> 5) + 0x24)

#define PWER_WE35   (1 << 24)

struct gpio_desc {
    unsigned    valid       : 1;
    unsigned    can_wakeup  : 1;
    unsigned    keypad_gpio : 1;
    unsigned    dir_inverted    : 1;
    unsigned int    mask; /* bit mask in PWER or PKWR */
    unsigned int    mux_mask; /* bit mask of muxed gpio bits, 0 if no mux */
    unsigned long   config;
};

static struct gpio_desc gpio_desc[MFP_PIN_GPIO127 + 1];

static unsigned long gpdr_lpm[4];

static int __mfp_config_gpio(unsigned gpio, unsigned long c)
{
    unsigned long gafr, mask = GPIO_bit(gpio);
    int bank = gpio_to_bank(gpio);
    int uorl = !!(gpio & 0x10); /* GAFRx_U or GAFRx_L ? */
    int shft = (gpio & 0xf) << 1;
    int fn = MFP_AF(c);
    int is_out = (c & MFP_DIR_OUT) ? 1 : 0;

    if (fn > 3)
        return -EINVAL;

    /* alternate function and direction at run-time */
    gafr = (uorl == 0) ? GAFR_L(bank) : GAFR_U(bank);
    gafr = (gafr & ~(0x3 << shft)) | (fn << shft);

    if (uorl == 0)
        GAFR_L(bank) = gafr;
    else
        GAFR_U(bank) = gafr;

    if (is_out ^ gpio_desc[gpio].dir_inverted)
        GPDR(gpio) |= mask;
    else
        GPDR(gpio) &= ~mask;

    /* alternate function and direction at low power mode */
    switch (c & MFP_LPM_STATE_MASK) {
    case MFP_LPM_DRIVE_HIGH:
        PGSR(bank) |= mask;
        is_out = 1;
        break;
    case MFP_LPM_DRIVE_LOW:
        PGSR(bank) &= ~mask;
        is_out = 1;
        break;
    case MFP_LPM_INPUT:
    case MFP_LPM_DEFAULT:
        break;
    default:
        /* warning and fall through, treat as MFP_LPM_DEFAULT */
        pr_warning("%s: GPIO%d: unsupported low power mode\n",
                __func__, gpio);
        break;
    }

    if (is_out ^ gpio_desc[gpio].dir_inverted)
        gpdr_lpm[bank] |= mask;
    else
        gpdr_lpm[bank] &= ~mask;

    /* give early warning if MFP_LPM_CAN_WAKEUP is set on the
     * configurations of those pins not able to wakeup
     */
    if ((c & MFP_LPM_CAN_WAKEUP) && !gpio_desc[gpio].can_wakeup) {
        pr_warning("%s: GPIO%d unable to wakeup\n",
                __func__, gpio);
        return -EINVAL;
    }

    if ((c & MFP_LPM_CAN_WAKEUP) && is_out) {
        pr_warning("%s: output GPIO%d unable to wakeup\n",
                __func__, gpio);
        return -EINVAL;
    }

    return 0;
}

static inline int __mfp_validate(int mfp)
{
    int gpio = mfp_to_gpio(mfp);

    if ((mfp > MFP_PIN_GPIO127) || !gpio_desc[gpio].valid) {
        pr_warning("%s: GPIO%d is invalid pin\n", __func__, gpio);
        return -1;
    }

    return gpio;
}

void pxa2xx_mfp_config(unsigned long *mfp_cfgs, int num)
{
    unsigned long flags;
    unsigned long *c;
    int i, gpio;

    for (i = 0, c = mfp_cfgs; i < num; i++, c++) {

        gpio = __mfp_validate(MFP_PIN(*c));
        if (gpio < 0)
            continue;

        local_irq_save(flags);

        gpio_desc[gpio].config = *c;
        __mfp_config_gpio(gpio, *c);

        local_irq_restore(flags);
    }
}

void pxa2xx_mfp_set_lpm(int mfp, unsigned long lpm)
{
    unsigned long flags, c;
    int gpio;

    gpio = __mfp_validate(mfp);
    if (gpio < 0)
        return;

    local_irq_save(flags);

    c = gpio_desc[gpio].config;
    c = (c & ~MFP_LPM_STATE_MASK) | lpm;
    __mfp_config_gpio(gpio, c);

    local_irq_restore(flags);
}

int gpio_set_wake(unsigned int gpio, unsigned int on)
{
    struct gpio_desc *d;
    unsigned long c, mux_taken;

    if (gpio > mfp_to_gpio(MFP_PIN_GPIO127))
        return -EINVAL;

    d = &gpio_desc[gpio];
    c = d->config;

    if (!d->valid)
        return -EINVAL;

    /* Allow keypad GPIOs to wakeup system when
     * configured as generic GPIOs.
     */
    if (d->keypad_gpio && (MFP_AF(d->config) == 0) &&
        (d->config & MFP_LPM_CAN_WAKEUP)) {
        if (on)
            PKWR |= d->mask;
        else
            PKWR &= ~d->mask;
        return 0;
    }

    mux_taken = (PWER & d->mux_mask) & (~d->mask);
    if (on && mux_taken)
        return -EBUSY;

    if (d->can_wakeup && (c & MFP_LPM_CAN_WAKEUP)) {
        if (on) {
            PWER = (PWER & ~d->mux_mask) | d->mask;

            if (c & MFP_LPM_EDGE_RISE)
                PRER |= d->mask;
            else
                PRER &= ~d->mask;

            if (c & MFP_LPM_EDGE_FALL)
                PFER |= d->mask;
            else
                PFER &= ~d->mask;
        } else {
            PWER &= ~d->mask;
            PRER &= ~d->mask;
            PFER &= ~d->mask;
        }
    }
    return 0;
}

#ifdef CONFIG_PXA25x
static void __init pxa25x_mfp_init(void)
{
    int i;

    /* running before pxa_gpio_probe() */
#ifdef CONFIG_CPU_PXA26x
    pxa_last_gpio = 89;
#else
    pxa_last_gpio = 84;
#endif
    for (i = 0; i <= pxa_last_gpio; i++)
        gpio_desc[i].valid = 1;

    for (i = 0; i <= 15; i++) {
        gpio_desc[i].can_wakeup = 1;
        gpio_desc[i].mask = GPIO_bit(i);
    }

    /* PXA26x has additional 4 GPIOs (86/87/88/89) which has the
     * direction bit inverted in GPDR2. See PXA26x DM 4.1.1.
     */
    for (i = 86; i <= pxa_last_gpio; i++)
        gpio_desc[i].dir_inverted = 1;
}
#else
static inline void pxa25x_mfp_init(void) {}
#endif /* CONFIG_PXA25x */

#ifdef CONFIG_PXA27x
static int pxa27x_pkwr_gpio[] = {
    13, 16, 17, 34, 36, 37, 38, 39, 90, 91, 93, 94,
    95, 96, 97, 98, 99, 100, 101, 102
};

int keypad_set_wake(unsigned int on)
{
    unsigned int i, gpio, mask = 0;
    struct gpio_desc *d;

    for (i = 0; i < ARRAY_SIZE(pxa27x_pkwr_gpio); i++) {

        gpio = pxa27x_pkwr_gpio[i];
        d = &gpio_desc[gpio];

        /* skip if configured as generic GPIO */
        if (MFP_AF(d->config) == 0)
            continue;

        if (d->config & MFP_LPM_CAN_WAKEUP)
            mask |= gpio_desc[gpio].mask;
    }

    if (on)
        PKWR |= mask;
    else
        PKWR &= ~mask;
    return 0;
}

#define PWER_WEMUX2_GPIO38  (1 << 16)
#define PWER_WEMUX2_GPIO53  (2 << 16)
#define PWER_WEMUX2_GPIO40  (3 << 16)
#define PWER_WEMUX2_GPIO36  (4 << 16)
#define PWER_WEMUX2_MASK    (7 << 16)
#define PWER_WEMUX3_GPIO31  (1 << 19)
#define PWER_WEMUX3_GPIO113 (2 << 19)
#define PWER_WEMUX3_MASK    (3 << 19)

#define INIT_GPIO_DESC_MUXED(mux, gpio)             \
do {                                \
    gpio_desc[(gpio)].can_wakeup = 1;           \
    gpio_desc[(gpio)].mask = PWER_ ## mux ## _GPIO ##gpio;  \
    gpio_desc[(gpio)].mux_mask = PWER_ ## mux ## _MASK; \
} while (0)

static void __init pxa27x_mfp_init(void)
{
    int i, gpio;

    pxa_last_gpio = 120;    /* running before pxa_gpio_probe() */
    for (i = 0; i <= pxa_last_gpio; i++) {
        /* skip GPIO2, 5, 6, 7, 8, they are not
         * valid pins allow configuration
         */
        if (i == 2 || i == 5 || i == 6 || i == 7 || i == 8)
            continue;

        gpio_desc[i].valid = 1;
    }

    /* Keypad GPIOs */
    for (i = 0; i < ARRAY_SIZE(pxa27x_pkwr_gpio); i++) {
        gpio = pxa27x_pkwr_gpio[i];
        gpio_desc[gpio].can_wakeup = 1;
        gpio_desc[gpio].keypad_gpio = 1;
        gpio_desc[gpio].mask = 1 << i;
    }

    /* Overwrite GPIO13 as a PWER wakeup source */
    for (i = 0; i <= 15; i++) {
        /* skip GPIO2, 5, 6, 7, 8 */
        if (GPIO_bit(i) & 0x1e4)
            continue;

        gpio_desc[i].can_wakeup = 1;
        gpio_desc[i].mask = GPIO_bit(i);
    }

    gpio_desc[35].can_wakeup = 1;
    gpio_desc[35].mask = PWER_WE35;

    INIT_GPIO_DESC_MUXED(WEMUX3, 31);
    INIT_GPIO_DESC_MUXED(WEMUX3, 113);
    INIT_GPIO_DESC_MUXED(WEMUX2, 38);
    INIT_GPIO_DESC_MUXED(WEMUX2, 53);
    INIT_GPIO_DESC_MUXED(WEMUX2, 40);
    INIT_GPIO_DESC_MUXED(WEMUX2, 36);
}
#else
static inline void pxa27x_mfp_init(void) {}
#endif /* CONFIG_PXA27x */

#ifdef CONFIG_PM
static unsigned long saved_gafr[2][4];
static unsigned long saved_gpdr[4];
static unsigned long saved_gplr[4];
static unsigned long saved_pgsr[4];

static int pxa2xx_mfp_suspend(void)
{
    int i;

    /* set corresponding PGSR bit of those marked MFP_LPM_KEEP_OUTPUT */
    for (i = 0; i < pxa_last_gpio; i++) {
        if ((gpio_desc[i].config & MFP_LPM_KEEP_OUTPUT) &&
            (GPDR(i) & GPIO_bit(i))) {
            if (GPLR(i) & GPIO_bit(i))
                PGSR(gpio_to_bank(i)) |= GPIO_bit(i);
            else
                PGSR(gpio_to_bank(i)) &= ~GPIO_bit(i);
        }
    }

    for (i = 0; i <= gpio_to_bank(pxa_last_gpio); i++) {
        saved_gafr[0][i] = GAFR_L(i);
        saved_gafr[1][i] = GAFR_U(i);
        saved_gpdr[i] = GPDR(i * 32);
        saved_gplr[i] = GPLR(i * 32);
        saved_pgsr[i] = PGSR(i);

        GPSR(i * 32) = PGSR(i);
        GPCR(i * 32) = ~PGSR(i);
    }

    /* set GPDR bits taking into account MFP_LPM_KEEP_OUTPUT */
    for (i = 0; i < pxa_last_gpio; i++) {
        if ((gpdr_lpm[gpio_to_bank(i)] & GPIO_bit(i)) ||
            ((gpio_desc[i].config & MFP_LPM_KEEP_OUTPUT) &&
             (saved_gpdr[gpio_to_bank(i)] & GPIO_bit(i))))
            GPDR(i) |= GPIO_bit(i);
        else
            GPDR(i) &= ~GPIO_bit(i);
    }

    return 0;
}

static void pxa2xx_mfp_resume(void)
{
    int i;

    for (i = 0; i <= gpio_to_bank(pxa_last_gpio); i++) {
        GAFR_L(i) = saved_gafr[0][i];
        GAFR_U(i) = saved_gafr[1][i];
        GPSR(i * 32) = saved_gplr[i];
        GPCR(i * 32) = ~saved_gplr[i];
        GPDR(i * 32) = saved_gpdr[i];
        PGSR(i) = saved_pgsr[i];
    }
    PSSR = PSSR_RDH | PSSR_PH;
}
#else
#define pxa2xx_mfp_suspend  NULL
#define pxa2xx_mfp_resume   NULL
#endif

struct syscore_ops pxa2xx_mfp_syscore_ops = {
    .suspend    = pxa2xx_mfp_suspend,
    .resume     = pxa2xx_mfp_resume,
};

static int __init pxa2xx_mfp_init(void)
{
    int i;

    if (!cpu_is_pxa2xx())
        return 0;

    if (cpu_is_pxa25x())
        pxa25x_mfp_init();

    if (cpu_is_pxa27x())
        pxa27x_mfp_init();

    /* clear RDH bit to enable GPIO receivers after reset/sleep exit */
    PSSR = PSSR_RDH;

    /* initialize gafr_run[], pgsr_lpm[] from existing values */
    for (i = 0; i <= gpio_to_bank(pxa_last_gpio); i++)
        gpdr_lpm[i] = GPDR(i * 32);

    return 0;
}
postcore_initcall(pxa2xx_mfp_init);