am300epd.c

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/*
 * am300epd.c -- Platform device for AM300 EPD kit
 *
 * Copyright (C) 2008, Jaya Kumar
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License. See the file COPYING in the main directory of this archive for
 * more details.
 *
 * This work was made possible by help and equipment support from E-Ink
 * Corporation. http://support.eink.com/community
 *
 * This driver is written to be used with the Broadsheet display controller.
 * on the AM300 EPD prototype kit/development kit with an E-Ink 800x600
 * Vizplex EPD on a Gumstix board using the Broadsheet interface board.
 *
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/fb.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/irq.h>
#include <linux/gpio.h>

#include <mach/gumstix.h>
#include <mach/mfp-pxa25x.h>
#include <linux/platform_data/video-pxafb.h>

#include "generic.h"

#include <video/broadsheetfb.h>

static unsigned int panel_type = 6;
static struct platform_device *am300_device;
static struct broadsheet_board am300_board;

static unsigned long am300_pin_config[] __initdata = {
    GPIO16_GPIO,
    GPIO17_GPIO,
    GPIO32_GPIO,
    GPIO48_GPIO,
    GPIO49_GPIO,
    GPIO51_GPIO,
    GPIO74_GPIO,
    GPIO75_GPIO,
    GPIO76_GPIO,
    GPIO77_GPIO,

    /* this is the 16-bit hdb bus 58-73 */
    GPIO58_GPIO,
    GPIO59_GPIO,
    GPIO60_GPIO,
    GPIO61_GPIO,

    GPIO62_GPIO,
    GPIO63_GPIO,
    GPIO64_GPIO,
    GPIO65_GPIO,

    GPIO66_GPIO,
    GPIO67_GPIO,
    GPIO68_GPIO,
    GPIO69_GPIO,

    GPIO70_GPIO,
    GPIO71_GPIO,
    GPIO72_GPIO,
    GPIO73_GPIO,
};

/* register offsets for gpio control */
#define PWR_GPIO_PIN    16
#define CFG_GPIO_PIN    17
#define RDY_GPIO_PIN    32
#define DC_GPIO_PIN 48
#define RST_GPIO_PIN    49
#define LED_GPIO_PIN    51
#define RD_GPIO_PIN 74
#define WR_GPIO_PIN 75
#define CS_GPIO_PIN 76
#define IRQ_GPIO_PIN    77

/* hdb bus */
#define DB0_GPIO_PIN    58
#define DB15_GPIO_PIN   73

static int gpios[] = { PWR_GPIO_PIN, CFG_GPIO_PIN, RDY_GPIO_PIN, DC_GPIO_PIN,
            RST_GPIO_PIN, RD_GPIO_PIN, WR_GPIO_PIN, CS_GPIO_PIN,
            IRQ_GPIO_PIN, LED_GPIO_PIN };
static char *gpio_names[] = { "PWR", "CFG", "RDY", "DC", "RST", "RD", "WR",
                "CS", "IRQ", "LED" };

static int am300_wait_event(struct broadsheetfb_par *par)
{
    /* todo: improve err recovery */
    wait_event(par->waitq, gpio_get_value(RDY_GPIO_PIN));
    return 0;
}

static int am300_init_gpio_regs(struct broadsheetfb_par *par)
{
    int i;
    int err;
    char dbname[8];

    for (i = 0; i < ARRAY_SIZE(gpios); i++) {
        err = gpio_request(gpios[i], gpio_names[i]);
        if (err) {
            dev_err(&am300_device->dev, "failed requesting "
                "gpio %s, err=%d\n", gpio_names[i], err);
            goto err_req_gpio;
        }
    }

    /* we also need to take care of the hdb bus */
    for (i = DB0_GPIO_PIN; i <= DB15_GPIO_PIN; i++) {
        sprintf(dbname, "DB%d", i);
        err = gpio_request(i, dbname);
        if (err) {
            dev_err(&am300_device->dev, "failed requesting "
                "gpio %d, err=%d\n", i, err);
            goto err_req_gpio2;
        }
    }

    /* setup the outputs and init values */
    gpio_direction_output(PWR_GPIO_PIN, 0);
    gpio_direction_output(CFG_GPIO_PIN, 1);
    gpio_direction_output(DC_GPIO_PIN, 0);
    gpio_direction_output(RD_GPIO_PIN, 1);
    gpio_direction_output(WR_GPIO_PIN, 1);
    gpio_direction_output(CS_GPIO_PIN, 1);
    gpio_direction_output(RST_GPIO_PIN, 0);

    /* setup the inputs */
    gpio_direction_input(RDY_GPIO_PIN);
    gpio_direction_input(IRQ_GPIO_PIN);

    /* start the hdb bus as an input */
    for (i = DB0_GPIO_PIN; i <= DB15_GPIO_PIN; i++)
        gpio_direction_output(i, 0);

    /* go into command mode */
    gpio_set_value(CFG_GPIO_PIN, 1);
    gpio_set_value(RST_GPIO_PIN, 0);
    msleep(10);
    gpio_set_value(RST_GPIO_PIN, 1);
    msleep(10);
    am300_wait_event(par);

    return 0;

err_req_gpio2:
    while (--i >= DB0_GPIO_PIN)
        gpio_free(i);
    i = ARRAY_SIZE(gpios);
err_req_gpio:
    while (--i >= 0)
        gpio_free(gpios[i]);

    return err;
}

static int am300_init_board(struct broadsheetfb_par *par)
{
    return am300_init_gpio_regs(par);
}

static void am300_cleanup(struct broadsheetfb_par *par)
{
    int i;

    free_irq(PXA_GPIO_TO_IRQ(RDY_GPIO_PIN), par);

    for (i = 0; i < ARRAY_SIZE(gpios); i++)
        gpio_free(gpios[i]);

    for (i = DB0_GPIO_PIN; i <= DB15_GPIO_PIN; i++)
        gpio_free(i);

}

static u16 am300_get_hdb(struct broadsheetfb_par *par)
{
    u16 res = 0;
    int i;

    for (i = 0; i <= (DB15_GPIO_PIN - DB0_GPIO_PIN) ; i++)
        res |= (gpio_get_value(DB0_GPIO_PIN + i)) ? (1 << i) : 0;

    return res;
}

static void am300_set_hdb(struct broadsheetfb_par *par, u16 data)
{
    int i;

    for (i = 0; i <= (DB15_GPIO_PIN - DB0_GPIO_PIN) ; i++)
        gpio_set_value(DB0_GPIO_PIN + i, (data >> i) & 0x01);
}


static void am300_set_ctl(struct broadsheetfb_par *par, unsigned char bit,
                u8 state)
{
    switch (bit) {
    case BS_CS:
        gpio_set_value(CS_GPIO_PIN, state);
        break;
    case BS_DC:
        gpio_set_value(DC_GPIO_PIN, state);
        break;
    case BS_WR:
        gpio_set_value(WR_GPIO_PIN, state);
        break;
    }
}

static int am300_get_panel_type(void)
{
    return panel_type;
}

static irqreturn_t am300_handle_irq(int irq, void *dev_id)
{
    struct broadsheetfb_par *par = dev_id;

    wake_up(&par->waitq);
    return IRQ_HANDLED;
}

static int am300_setup_irq(struct fb_info *info)
{
    int ret;
    struct broadsheetfb_par *par = info->par;

    ret = request_irq(PXA_GPIO_TO_IRQ(RDY_GPIO_PIN), am300_handle_irq,
                IRQF_DISABLED|IRQF_TRIGGER_RISING,
                "AM300", par);
    if (ret)
        dev_err(&am300_device->dev, "request_irq failed: %d\n", ret);

    return ret;
}

static struct broadsheet_board am300_board = {
    .owner          = THIS_MODULE,
    .init           = am300_init_board,
    .cleanup        = am300_cleanup,
    .set_hdb        = am300_set_hdb,
    .get_hdb        = am300_get_hdb,
    .set_ctl        = am300_set_ctl,
    .wait_for_rdy       = am300_wait_event,
    .get_panel_type     = am300_get_panel_type,
    .setup_irq      = am300_setup_irq,
};

int __init am300_init(void)
{
    int ret;

    pxa2xx_mfp_config(ARRAY_AND_SIZE(am300_pin_config));

    /* request our platform independent driver */
    request_module("broadsheetfb");

    am300_device = platform_device_alloc("broadsheetfb", -1);
    if (!am300_device)
        return -ENOMEM;

    /* the am300_board that will be seen by broadsheetfb is a copy */
    platform_device_add_data(am300_device, &am300_board,
                    sizeof(am300_board));

    ret = platform_device_add(am300_device);

    if (ret) {
        platform_device_put(am300_device);
        return ret;
    }

    return 0;
}

module_param(panel_type, uint, 0);
MODULE_PARM_DESC(panel_type, "Select the panel type: 37, 6, 97");

MODULE_DESCRIPTION("board driver for am300 epd kit");
MODULE_AUTHOR("Jaya Kumar");
MODULE_LICENSE("GPL");