drivers/mmc/host/of_mmc_spi.c

   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
  33 MODULE_LICENSE("GPL");
  34
  35 enum {
  36         CD_GPIO = 0,
  37         WP_GPIO,
  38         NUM_GPIOS,
  39 };
  40
  41 struct 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
  48 static 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
  53 static 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
  62 static 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
  69 struct 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 u32 *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;
 139 err_ocr:
 140         kfree(oms);
 141         return NULL;
 142 }
 143 EXPORT_SYMBOL(mmc_spi_get_pdata);
 144
 145 void 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 }
 157 EXPORT_SYMBOL(mmc_spi_put_pdata);