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_read_gpio(struct device *dev, int gpio_num) 54 { 55 struct of_mmc_spi *oms = to_of_mmc_spi(dev); 56 bool active_low = oms->alow_gpios[gpio_num]; 57 bool value = gpio_get_value(oms->gpios[gpio_num]); 58 59 return active_low ^ value; 60 } 61 62 static int of_mmc_spi_get_cd(struct device *dev) 63 { 64 return of_mmc_spi_read_gpio(dev, CD_GPIO); 65 } 66 67 static int of_mmc_spi_get_ro(struct device *dev) 68 { 69 return of_mmc_spi_read_gpio(dev, WP_GPIO); 70 } 71 72 static int of_mmc_spi_init(struct device *dev, 73 irqreturn_t (*irqhandler)(int, void *), void *mmc) 74 { 75 struct of_mmc_spi *oms = to_of_mmc_spi(dev); 76 77 return request_threaded_irq(oms->detect_irq, NULL, irqhandler, 0, 78 dev_name(dev), mmc); 79 } 80 81 static void of_mmc_spi_exit(struct device *dev, void *mmc) 82 { 83 struct of_mmc_spi *oms = to_of_mmc_spi(dev); 84 85 free_irq(oms->detect_irq, mmc); 86 } 87 88 struct mmc_spi_platform_data *mmc_spi_get_pdata(struct spi_device *spi) 89 { 90 struct device *dev = &spi->dev; 91 struct device_node *np = dev->of_node; 92 struct of_mmc_spi *oms; 93 const u32 *voltage_ranges; 94 int num_ranges; 95 int i; 96 int ret = -EINVAL; 97 98 if (dev->platform_data || !np) 99 return dev->platform_data; 100 101 oms = kzalloc(sizeof(*oms), GFP_KERNEL); 102 if (!oms) 103 return NULL; 104 105 voltage_ranges = of_get_property(np, "voltage-ranges", &num_ranges); 106 num_ranges = num_ranges / sizeof(*voltage_ranges) / 2; 107 if (!voltage_ranges || !num_ranges) { 108 dev_err(dev, "OF: voltage-ranges unspecified\n"); 109 goto err_ocr; 110 } 111 112 for (i = 0; i < num_ranges; i++) { 113 const int j = i * 2; 114 u32 mask; 115 116 mask = mmc_vddrange_to_ocrmask(be32_to_cpu(voltage_ranges[j]), 117 be32_to_cpu(voltage_ranges[j + 1])); 118 if (!mask) { 119 ret = -EINVAL; 120 dev_err(dev, "OF: voltage-range #%d is invalid\n", i); 121 goto err_ocr; 122 } 123 oms->pdata.ocr_mask |= mask; 124 } 125 126 for (i = 0; i < ARRAY_SIZE(oms->gpios); i++) { 127 enum of_gpio_flags gpio_flags; 128 129 oms->gpios[i] = of_get_gpio_flags(np, i, &gpio_flags); 130 if (!gpio_is_valid(oms->gpios[i])) 131 continue; 132 133 ret = gpio_request(oms->gpios[i], dev_name(dev)); 134 if (ret < 0) { 135 oms->gpios[i] = -EINVAL; 136 continue; 137 } 138 139 if (gpio_flags & OF_GPIO_ACTIVE_LOW) 140 oms->alow_gpios[i] = true; 141 } 142 143 if (gpio_is_valid(oms->gpios[CD_GPIO])) 144 oms->pdata.get_cd = of_mmc_spi_get_cd; 145 if (gpio_is_valid(oms->gpios[WP_GPIO])) 146 oms->pdata.get_ro = of_mmc_spi_get_ro; 147 148 oms->detect_irq = irq_of_parse_and_map(np, 0); 149 if (oms->detect_irq != NO_IRQ) { 150 oms->pdata.init = of_mmc_spi_init; 151 oms->pdata.exit = of_mmc_spi_exit; 152 } else { 153 oms->pdata.caps |= MMC_CAP_NEEDS_POLL; 154 } 155 156 dev->platform_data = &oms->pdata; 157 return dev->platform_data; 158 err_ocr: 159 kfree(oms); 160 return NULL; 161 } 162 EXPORT_SYMBOL(mmc_spi_get_pdata); 163 164 void mmc_spi_put_pdata(struct spi_device *spi) 165 { 166 struct device *dev = &spi->dev; 167 struct device_node *np = dev->of_node; 168 struct of_mmc_spi *oms = to_of_mmc_spi(dev); 169 int i; 170 171 if (!dev->platform_data || !np) 172 return; 173 174 for (i = 0; i < ARRAY_SIZE(oms->gpios); i++) { 175 if (gpio_is_valid(oms->gpios[i])) 176 gpio_free(oms->gpios[i]); 177 } 178 kfree(oms); 179 dev->platform_data = NULL; 180 } 181 EXPORT_SYMBOL(mmc_spi_put_pdata); 182