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, 0,
  59                                     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         int ret = -EINVAL;
  78
  79         if (dev->platform_data || !np)
  80                 return dev->platform_data;
  81
  82         oms = kzalloc(sizeof(*oms), GFP_KERNEL);
  83         if (!oms)
  84                 return NULL;
  85
  86         voltage_ranges = of_get_property(np, "voltage-ranges", &num_ranges);
  87         num_ranges = num_ranges / sizeof(*voltage_ranges) / 2;
  88         if (!voltage_ranges || !num_ranges) {
  89                 dev_err(dev, "OF: voltage-ranges unspecified\n");
  90                 goto err_ocr;
  91         }
  92
  93         for (i = 0; i < num_ranges; i++) {
  94                 const int j = i * 2;
  95                 u32 mask;
  96
  97                 mask = mmc_vddrange_to_ocrmask(be32_to_cpu(voltage_ranges[j]),
  98                                                be32_to_cpu(voltage_ranges[j + 1]));
  99                 if (!mask) {
 100                         ret = -EINVAL;
 101                         dev_err(dev, "OF: voltage-range #%d is invalid\n", i);
 102                         goto err_ocr;
 103                 }
 104                 oms->pdata.ocr_mask |= mask;
 105         }
 106
 107         for (i = 0; i < ARRAY_SIZE(oms->gpios); i++) {
 108                 enum of_gpio_flags gpio_flags;
 109
 110                 oms->gpios[i] = of_get_gpio_flags(np, i, &gpio_flags);
 111                 if (!gpio_is_valid(oms->gpios[i]))
 112                         continue;
 113
 114                 if (gpio_flags & OF_GPIO_ACTIVE_LOW)
 115                         oms->alow_gpios[i] = true;
 116         }
 117
 118         if (gpio_is_valid(oms->gpios[CD_GPIO])) {
 119                 oms->pdata.cd_gpio = oms->gpios[CD_GPIO];
 120                 oms->pdata.flags |= MMC_SPI_USE_CD_GPIO;
 121                 if (!oms->alow_gpios[CD_GPIO])
 122                         oms->pdata.caps2 |= MMC_CAP2_CD_ACTIVE_HIGH;
 123         }
 124         if (gpio_is_valid(oms->gpios[WP_GPIO])) {
 125                 oms->pdata.ro_gpio = oms->gpios[WP_GPIO];
 126                 oms->pdata.flags |= MMC_SPI_USE_RO_GPIO;
 127                 if (!oms->alow_gpios[WP_GPIO])
 128                         oms->pdata.caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;
 129         }
 130
 131         oms->detect_irq = irq_of_parse_and_map(np, 0);
 132         if (oms->detect_irq != 0) {
 133                 oms->pdata.init = of_mmc_spi_init;
 134                 oms->pdata.exit = of_mmc_spi_exit;
 135         } else {
 136                 oms->pdata.caps |= MMC_CAP_NEEDS_POLL;
 137         }
 138
 139         dev->platform_data = &oms->pdata;
 140         return dev->platform_data;
 141 err_ocr:
 142         kfree(oms);
 143         return NULL;
 144 }
 145 EXPORT_SYMBOL(mmc_spi_get_pdata);
 146
 147 void mmc_spi_put_pdata(struct spi_device *spi)
 148 {
 149         struct device *dev = &spi->dev;
 150         struct device_node *np = dev->of_node;
 151         struct of_mmc_spi *oms = to_of_mmc_spi(dev);
 152
 153         if (!dev->platform_data || !np)
 154                 return;
 155
 156         kfree(oms);
 157         dev->platform_data = NULL;
 158 }
 159 EXPORT_SYMBOL(mmc_spi_put_pdata);