linux/drivers/mmc/host/of_mmc_spi.c

182 lines
4.2 KiB
C

/*
* OpenFirmware bindings for the MMC-over-SPI driver
*
* Copyright (c) MontaVista Software, Inc. 2008.
*
* Author: Anton Vorontsov <avorontsov@ru.mvista.com>
*
* 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.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/irq.h>
#include <linux/gpio.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/of_irq.h>
#include <linux/spi/spi.h>
#include <linux/spi/mmc_spi.h>
#include <linux/mmc/core.h>
#include <linux/mmc/host.h>
/* For archs that don't support NO_IRQ (such as mips), provide a dummy value */
#ifndef NO_IRQ
#define NO_IRQ 0
#endif
MODULE_LICENSE("GPL");
enum {
CD_GPIO = 0,
WP_GPIO,
NUM_GPIOS,
};
struct of_mmc_spi {
int gpios[NUM_GPIOS];
bool alow_gpios[NUM_GPIOS];
int detect_irq;
struct mmc_spi_platform_data pdata;
};
static struct of_mmc_spi *to_of_mmc_spi(struct device *dev)
{
return container_of(dev->platform_data, struct of_mmc_spi, pdata);
}
static int of_mmc_spi_read_gpio(struct device *dev, int gpio_num)
{
struct of_mmc_spi *oms = to_of_mmc_spi(dev);
bool active_low = oms->alow_gpios[gpio_num];
bool value = gpio_get_value(oms->gpios[gpio_num]);
return active_low ^ value;
}
static int of_mmc_spi_get_cd(struct device *dev)
{
return of_mmc_spi_read_gpio(dev, CD_GPIO);
}
static int of_mmc_spi_get_ro(struct device *dev)
{
return of_mmc_spi_read_gpio(dev, WP_GPIO);
}
static int of_mmc_spi_init(struct device *dev,
irqreturn_t (*irqhandler)(int, void *), void *mmc)
{
struct of_mmc_spi *oms = to_of_mmc_spi(dev);
return request_threaded_irq(oms->detect_irq, NULL, irqhandler, 0,
dev_name(dev), mmc);
}
static void of_mmc_spi_exit(struct device *dev, void *mmc)
{
struct of_mmc_spi *oms = to_of_mmc_spi(dev);
free_irq(oms->detect_irq, mmc);
}
struct mmc_spi_platform_data *mmc_spi_get_pdata(struct spi_device *spi)
{
struct device *dev = &spi->dev;
struct device_node *np = dev->of_node;
struct of_mmc_spi *oms;
const u32 *voltage_ranges;
int num_ranges;
int i;
int ret = -EINVAL;
if (dev->platform_data || !np)
return dev->platform_data;
oms = kzalloc(sizeof(*oms), GFP_KERNEL);
if (!oms)
return NULL;
voltage_ranges = of_get_property(np, "voltage-ranges", &num_ranges);
num_ranges = num_ranges / sizeof(*voltage_ranges) / 2;
if (!voltage_ranges || !num_ranges) {
dev_err(dev, "OF: voltage-ranges unspecified\n");
goto err_ocr;
}
for (i = 0; i < num_ranges; i++) {
const int j = i * 2;
u32 mask;
mask = mmc_vddrange_to_ocrmask(voltage_ranges[j],
voltage_ranges[j + 1]);
if (!mask) {
ret = -EINVAL;
dev_err(dev, "OF: voltage-range #%d is invalid\n", i);
goto err_ocr;
}
oms->pdata.ocr_mask |= mask;
}
for (i = 0; i < ARRAY_SIZE(oms->gpios); i++) {
enum of_gpio_flags gpio_flags;
oms->gpios[i] = of_get_gpio_flags(np, i, &gpio_flags);
if (!gpio_is_valid(oms->gpios[i]))
continue;
ret = gpio_request(oms->gpios[i], dev_name(dev));
if (ret < 0) {
oms->gpios[i] = -EINVAL;
continue;
}
if (gpio_flags & OF_GPIO_ACTIVE_LOW)
oms->alow_gpios[i] = true;
}
if (gpio_is_valid(oms->gpios[CD_GPIO]))
oms->pdata.get_cd = of_mmc_spi_get_cd;
if (gpio_is_valid(oms->gpios[WP_GPIO]))
oms->pdata.get_ro = of_mmc_spi_get_ro;
oms->detect_irq = irq_of_parse_and_map(np, 0);
if (oms->detect_irq != NO_IRQ) {
oms->pdata.init = of_mmc_spi_init;
oms->pdata.exit = of_mmc_spi_exit;
} else {
oms->pdata.caps |= MMC_CAP_NEEDS_POLL;
}
dev->platform_data = &oms->pdata;
return dev->platform_data;
err_ocr:
kfree(oms);
return NULL;
}
EXPORT_SYMBOL(mmc_spi_get_pdata);
void mmc_spi_put_pdata(struct spi_device *spi)
{
struct device *dev = &spi->dev;
struct device_node *np = dev->of_node;
struct of_mmc_spi *oms = to_of_mmc_spi(dev);
int i;
if (!dev->platform_data || !np)
return;
for (i = 0; i < ARRAY_SIZE(oms->gpios); i++) {
if (gpio_is_valid(oms->gpios[i]))
gpio_free(oms->gpios[i]);
}
kfree(oms);
dev->platform_data = NULL;
}
EXPORT_SYMBOL(mmc_spi_put_pdata);