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/gpio.h> 19 #include <linux/of.h> 20 #include <linux/of_gpio.h> 21 #include <linux/spi/spi.h> 22 #include <linux/spi/mmc_spi.h> 23 #include <linux/mmc/core.h> 24 #include <linux/mmc/host.h> 25 26 MODULE_LICENSE("GPL"); 27 28 enum { 29 CD_GPIO = 0, 30 WP_GPIO, 31 NUM_GPIOS, 32 }; 33 34 struct of_mmc_spi { 35 int gpios[NUM_GPIOS]; 36 bool alow_gpios[NUM_GPIOS]; 37 int detect_irq; 38 struct mmc_spi_platform_data pdata; 39 }; 40 41 static struct of_mmc_spi *to_of_mmc_spi(struct device *dev) 42 { 43 return container_of(dev->platform_data, struct of_mmc_spi, pdata); 44 } 45 46 static int of_mmc_spi_read_gpio(struct device *dev, int gpio_num) 47 { 48 struct of_mmc_spi *oms = to_of_mmc_spi(dev); 49 bool active_low = oms->alow_gpios[gpio_num]; 50 bool value = gpio_get_value(oms->gpios[gpio_num]); 51 52 return active_low ^ value; 53 } 54 55 static int of_mmc_spi_get_cd(struct device *dev) 56 { 57 return of_mmc_spi_read_gpio(dev, CD_GPIO); 58 } 59 60 static int of_mmc_spi_get_ro(struct device *dev) 61 { 62 return of_mmc_spi_read_gpio(dev, WP_GPIO); 63 } 64 65 static int of_mmc_spi_init(struct device *dev, 66 irqreturn_t (*irqhandler)(int, void *), void *mmc) 67 { 68 struct of_mmc_spi *oms = to_of_mmc_spi(dev); 69 70 return request_threaded_irq(oms->detect_irq, NULL, irqhandler, 0, 71 dev_name(dev), mmc); 72 } 73 74 static void of_mmc_spi_exit(struct device *dev, void *mmc) 75 { 76 struct of_mmc_spi *oms = to_of_mmc_spi(dev); 77 78 free_irq(oms->detect_irq, mmc); 79 } 80 81 struct mmc_spi_platform_data *mmc_spi_get_pdata(struct spi_device *spi) 82 { 83 struct device *dev = &spi->dev; 84 struct device_node *np = dev->of_node; 85 struct of_mmc_spi *oms; 86 const u32 *voltage_ranges; 87 int num_ranges; 88 int i; 89 int ret = -EINVAL; 90 91 if (dev->platform_data || !np) 92 return dev->platform_data; 93 94 oms = kzalloc(sizeof(*oms), GFP_KERNEL); 95 if (!oms) 96 return NULL; 97 98 voltage_ranges = of_get_property(np, "voltage-ranges", &num_ranges); 99 num_ranges = num_ranges / sizeof(*voltage_ranges) / 2; 100 if (!voltage_ranges || !num_ranges) { 101 dev_err(dev, "OF: voltage-ranges unspecified\n"); 102 goto err_ocr; 103 } 104 105 for (i = 0; i < num_ranges; i++) { 106 const int j = i * 2; 107 u32 mask; 108 109 mask = mmc_vddrange_to_ocrmask(voltage_ranges[j], 110 voltage_ranges[j + 1]); 111 if (!mask) { 112 ret = -EINVAL; 113 dev_err(dev, "OF: voltage-range #%d is invalid\n", i); 114 goto err_ocr; 115 } 116 oms->pdata.ocr_mask |= mask; 117 } 118 119 for (i = 0; i < ARRAY_SIZE(oms->gpios); i++) { 120 enum of_gpio_flags gpio_flags; 121 122 oms->gpios[i] = of_get_gpio_flags(np, i, &gpio_flags); 123 if (!gpio_is_valid(oms->gpios[i])) 124 continue; 125 126 ret = gpio_request(oms->gpios[i], dev_name(dev)); 127 if (ret < 0) { 128 oms->gpios[i] = -EINVAL; 129 continue; 130 } 131 132 if (gpio_flags & OF_GPIO_ACTIVE_LOW) 133 oms->alow_gpios[i] = true; 134 } 135 136 if (gpio_is_valid(oms->gpios[CD_GPIO])) 137 oms->pdata.get_cd = of_mmc_spi_get_cd; 138 if (gpio_is_valid(oms->gpios[WP_GPIO])) 139 oms->pdata.get_ro = of_mmc_spi_get_ro; 140 141 oms->detect_irq = irq_of_parse_and_map(np, 0); 142 if (oms->detect_irq != NO_IRQ) { 143 oms->pdata.init = of_mmc_spi_init; 144 oms->pdata.exit = of_mmc_spi_exit; 145 } else { 146 oms->pdata.caps |= MMC_CAP_NEEDS_POLL; 147 } 148 149 dev->platform_data = &oms->pdata; 150 return dev->platform_data; 151 err_ocr: 152 kfree(oms); 153 return NULL; 154 } 155 EXPORT_SYMBOL(mmc_spi_get_pdata); 156 157 void mmc_spi_put_pdata(struct spi_device *spi) 158 { 159 struct device *dev = &spi->dev; 160 struct device_node *np = dev->of_node; 161 struct of_mmc_spi *oms = to_of_mmc_spi(dev); 162 int i; 163 164 if (!dev->platform_data || !np) 165 return; 166 167 for (i = 0; i < ARRAY_SIZE(oms->gpios); i++) { 168 if (gpio_is_valid(oms->gpios[i])) 169 gpio_free(oms->gpios[i]); 170 } 171 kfree(oms); 172 dev->platform_data = NULL; 173 } 174 EXPORT_SYMBOL(mmc_spi_put_pdata); 175