LXR linux/drivers/mmc/host/of_mmc

   1/*
   2 * OpenFirmware bindings for the MMC-over-SPI driver
   3 *
   4 * Copyright (c) MontaVista Software, Inc. 2008.
   5 *
   6 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
   7 *
   8 * This program is free software; you can redistribute  it and/or modify it
   9 * under  the terms of  the GNU General  Public License as published by the
  10 * Free Software Foundation;  either version 2 of the  License, or (at your
  11 * option) any later version.
  12 */
  13
  14#include <linux/kernel.h>
  15#include <linux/module.h>
  16#include <linux/device.h>
  17#include <linux/slab.h>
  18#include <linux/irq.h>
  19#include <linux/gpio.h>
  20#include <linux/of.h>
  21#include <linux/of_gpio.h>
  22#include <linux/of_irq.h>
  23#include <linux/spi/spi.h>
  24#include <linux/spi/mmc_spi.h>
  25#include <linux/mmc/core.h>
  26#include <linux/mmc/host.h>
  27
  28/* For archs that don't support NO_IRQ (such as mips), provide a dummy value */
  29#ifndef NO_IRQ
  30#define NO_IRQ 0
  31#endif
  32
  33MODULE_LICENSE("GPL");
  34
  35enum {
  36        CD_GPIO = 0,
  37        WP_GPIO,
  38        NUM_GPIOS,
  39};
  40
  41struct of_mmc_spi {
  42        int gpios[NUM_GPIOS];
  43        bool alow_gpios[NUM_GPIOS];
  44        int detect_irq;
  45        struct mmc_spi_platform_data pdata;
  46};
  47
  48static struct of_mmc_spi *to_of_mmc_spi(struct device *dev)
  49{
  50        return container_of(dev->platform_data, struct of_mmc_spi, pdata);
  51}
  52
  53static int of_mmc_spi_init(struct device *dev,
  54                           irqreturn_t (*irqhandler)(int, void *), void *mmc)
  55{
  56        struct of_mmc_spi *oms = to_of_mmc_spi(dev);
  57
  58        return request_threaded_irq(oms->detect_irq, NULL, irqhandler,
  59                                        IRQF_ONESHOT, dev_name(dev), mmc);
  60}
  61
  62static void of_mmc_spi_exit(struct device *dev, void *mmc)
  63{
  64        struct of_mmc_spi *oms = to_of_mmc_spi(dev);
  65
  66        free_irq(oms->detect_irq, mmc);
  67}
  68
  69struct mmc_spi_platform_data *mmc_spi_get_pdata(struct spi_device *spi)
  70{
  71        struct device *dev = &spi->dev;
  72        struct device_node *np = dev->of_node;
  73        struct of_mmc_spi *oms;
  74        const __be32 *voltage_ranges;
  75        int num_ranges;
  76        int i;
  77
  78        if (dev->platform_data || !np)
  79                return dev->platform_data;
  80
  81        oms = kzalloc(sizeof(*oms), GFP_KERNEL);
  82        if (!oms)
  83                return NULL;
  84
  85        voltage_ranges = of_get_property(np, "voltage-ranges", &num_ranges);
  86        num_ranges = num_ranges / sizeof(*voltage_ranges) / 2;
  87        if (!voltage_ranges || !num_ranges) {
  88                dev_err(dev, "OF: voltage-ranges unspecified\n");
  89                goto err_ocr;
  90        }
  91
  92        for (i = 0; i < num_ranges; i++) {
  93                const int j = i * 2;
  94                u32 mask;
  95
  96                mask = mmc_vddrange_to_ocrmask(be32_to_cpu(voltage_ranges[j]),
  97                                               be32_to_cpu(voltage_ranges[j + 1]));
  98                if (!mask) {
  99                        dev_err(dev, "OF: voltage-range #%d is invalid\n", i);
 100                        goto err_ocr;
 101                }
 102                oms->pdata.ocr_mask |= mask;
 103        }
 104
 105        for (i = 0; i < ARRAY_SIZE(oms->gpios); i++) {
 106                enum of_gpio_flags gpio_flags;
 107
 108                oms->gpios[i] = of_get_gpio_flags(np, i, &gpio_flags);
 109                if (!gpio_is_valid(oms->gpios[i]))
 110                        continue;
 111
 112                if (gpio_flags & OF_GPIO_ACTIVE_LOW)
 113                        oms->alow_gpios[i] = true;
 114        }
 115
 116        if (gpio_is_valid(oms->gpios[CD_GPIO])) {
 117                oms->pdata.cd_gpio = oms->gpios[CD_GPIO];
 118                oms->pdata.flags |= MMC_SPI_USE_CD_GPIO;
 119                if (!oms->alow_gpios[CD_GPIO])
 120                        oms->pdata.caps2 |= MMC_CAP2_CD_ACTIVE_HIGH;
 121        }
 122        if (gpio_is_valid(oms->gpios[WP_GPIO])) {
 123                oms->pdata.ro_gpio = oms->gpios[WP_GPIO];
 124                oms->pdata.flags |= MMC_SPI_USE_RO_GPIO;
 125                if (!oms->alow_gpios[WP_GPIO])
 126                        oms->pdata.caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;
 127        }
 128
 129        oms->detect_irq = irq_of_parse_and_map(np, 0);
 130        if (oms->detect_irq != 0) {
 131                oms->pdata.init = of_mmc_spi_init;
 132                oms->pdata.exit = of_mmc_spi_exit;
 133        } else {
 134                oms->pdata.caps |= MMC_CAP_NEEDS_POLL;
 135        }
 136
 137        dev->platform_data = &oms->pdata;
 138        return dev->platform_data;
 139err_ocr:
 140        kfree(oms);
 141        return NULL;
 142}
 143EXPORT_SYMBOL(mmc_spi_get_pdata);
 144
 145void mmc_spi_put_pdata(struct spi_device *spi)
 146{
 147        struct device *dev = &spi->dev;
 148        struct device_node *np = dev->of_node;
 149        struct of_mmc_spi *oms = to_of_mmc_spi(dev);
 150
 151        if (!dev->platform_data || !np)
 152                return;
 153
 154        kfree(oms);
 155        dev->platform_data = NULL;
 156}
 157EXPORT_SYMBOL(mmc_spi_put_pdata);
 158