Guennadi Liakhovetski | fd0ea65 | 2012-04-30 23:31:57 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Generic GPIO card-detect helper |
| 3 | * |
| 4 | * Copyright (C) 2011, Guennadi Liakhovetski <g.liakhovetski@gmx.de> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 as |
| 8 | * published by the Free Software Foundation. |
| 9 | */ |
| 10 | |
| 11 | #include <linux/err.h> |
| 12 | #include <linux/gpio.h> |
| 13 | #include <linux/interrupt.h> |
| 14 | #include <linux/jiffies.h> |
| 15 | #include <linux/mmc/host.h> |
| 16 | #include <linux/mmc/slot-gpio.h> |
| 17 | #include <linux/module.h> |
| 18 | #include <linux/slab.h> |
| 19 | |
| 20 | struct mmc_gpio { |
Guennadi Liakhovetski | 5aa7dad | 2012-05-01 16:59:38 +0200 | [diff] [blame] | 21 | int ro_gpio; |
Guennadi Liakhovetski | befe404 | 2012-05-01 16:27:25 +0200 | [diff] [blame] | 22 | int cd_gpio; |
Guennadi Liakhovetski | 5aa7dad | 2012-05-01 16:59:38 +0200 | [diff] [blame] | 23 | char *ro_label; |
Guennadi Liakhovetski | fd0ea65 | 2012-04-30 23:31:57 +0200 | [diff] [blame] | 24 | char cd_label[0]; |
| 25 | }; |
| 26 | |
| 27 | static irqreturn_t mmc_gpio_cd_irqt(int irq, void *dev_id) |
| 28 | { |
| 29 | /* Schedule a card detection after a debounce timeout */ |
Guennadi Liakhovetski | 451c895 | 2012-12-04 16:51:36 +0100 | [diff] [blame] | 30 | struct mmc_host *host = dev_id; |
| 31 | |
| 32 | if (host->ops->card_event) |
| 33 | host->ops->card_event(host); |
| 34 | |
| 35 | mmc_detect_change(host, msecs_to_jiffies(200)); |
| 36 | |
Guennadi Liakhovetski | fd0ea65 | 2012-04-30 23:31:57 +0200 | [diff] [blame] | 37 | return IRQ_HANDLED; |
| 38 | } |
| 39 | |
Guennadi Liakhovetski | a7d1a1e | 2012-05-01 16:51:38 +0200 | [diff] [blame] | 40 | static int mmc_gpio_alloc(struct mmc_host *host) |
| 41 | { |
| 42 | size_t len = strlen(dev_name(host->parent)) + 4; |
| 43 | struct mmc_gpio *ctx; |
| 44 | |
| 45 | mutex_lock(&host->slot.lock); |
| 46 | |
| 47 | ctx = host->slot.handler_priv; |
| 48 | if (!ctx) { |
| 49 | /* |
| 50 | * devm_kzalloc() can be called after device_initialize(), even |
| 51 | * before device_add(), i.e., between mmc_alloc_host() and |
| 52 | * mmc_add_host() |
| 53 | */ |
Guennadi Liakhovetski | 5aa7dad | 2012-05-01 16:59:38 +0200 | [diff] [blame] | 54 | ctx = devm_kzalloc(&host->class_dev, sizeof(*ctx) + 2 * len, |
Guennadi Liakhovetski | a7d1a1e | 2012-05-01 16:51:38 +0200 | [diff] [blame] | 55 | GFP_KERNEL); |
| 56 | if (ctx) { |
Guennadi Liakhovetski | 5aa7dad | 2012-05-01 16:59:38 +0200 | [diff] [blame] | 57 | ctx->ro_label = ctx->cd_label + len; |
Guennadi Liakhovetski | a7d1a1e | 2012-05-01 16:51:38 +0200 | [diff] [blame] | 58 | snprintf(ctx->cd_label, len, "%s cd", dev_name(host->parent)); |
Guennadi Liakhovetski | 5aa7dad | 2012-05-01 16:59:38 +0200 | [diff] [blame] | 59 | snprintf(ctx->ro_label, len, "%s ro", dev_name(host->parent)); |
Guennadi Liakhovetski | a7d1a1e | 2012-05-01 16:51:38 +0200 | [diff] [blame] | 60 | ctx->cd_gpio = -EINVAL; |
Guennadi Liakhovetski | 5aa7dad | 2012-05-01 16:59:38 +0200 | [diff] [blame] | 61 | ctx->ro_gpio = -EINVAL; |
Guennadi Liakhovetski | a7d1a1e | 2012-05-01 16:51:38 +0200 | [diff] [blame] | 62 | host->slot.handler_priv = ctx; |
| 63 | } |
| 64 | } |
| 65 | |
| 66 | mutex_unlock(&host->slot.lock); |
| 67 | |
| 68 | return ctx ? 0 : -ENOMEM; |
| 69 | } |
| 70 | |
Guennadi Liakhovetski | 5aa7dad | 2012-05-01 16:59:38 +0200 | [diff] [blame] | 71 | int mmc_gpio_get_ro(struct mmc_host *host) |
| 72 | { |
| 73 | struct mmc_gpio *ctx = host->slot.handler_priv; |
| 74 | |
| 75 | if (!ctx || !gpio_is_valid(ctx->ro_gpio)) |
| 76 | return -ENOSYS; |
| 77 | |
| 78 | return !gpio_get_value_cansleep(ctx->ro_gpio) ^ |
| 79 | !!(host->caps2 & MMC_CAP2_RO_ACTIVE_HIGH); |
| 80 | } |
| 81 | EXPORT_SYMBOL(mmc_gpio_get_ro); |
| 82 | |
Guennadi Liakhovetski | befe404 | 2012-05-01 16:27:25 +0200 | [diff] [blame] | 83 | int mmc_gpio_get_cd(struct mmc_host *host) |
| 84 | { |
| 85 | struct mmc_gpio *ctx = host->slot.handler_priv; |
| 86 | |
| 87 | if (!ctx || !gpio_is_valid(ctx->cd_gpio)) |
| 88 | return -ENOSYS; |
| 89 | |
| 90 | return !gpio_get_value_cansleep(ctx->cd_gpio) ^ |
| 91 | !!(host->caps2 & MMC_CAP2_CD_ACTIVE_HIGH); |
| 92 | } |
| 93 | EXPORT_SYMBOL(mmc_gpio_get_cd); |
| 94 | |
Shawn Guo | d65b5ae | 2012-12-11 22:32:18 +0800 | [diff] [blame] | 95 | /** |
| 96 | * mmc_gpio_request_ro - request a gpio for write-protection |
| 97 | * @host: mmc host |
| 98 | * @gpio: gpio number requested |
| 99 | * |
| 100 | * As devm_* managed functions are used in mmc_gpio_request_ro(), client |
| 101 | * drivers do not need to explicitly call mmc_gpio_free_ro() for freeing up, |
| 102 | * if the requesting and freeing are only needed at probing and unbinding time |
| 103 | * for once. However, if client drivers do something special like runtime |
| 104 | * switching for write-protection, they are responsible for calling |
| 105 | * mmc_gpio_request_ro() and mmc_gpio_free_ro() as a pair on their own. |
| 106 | * |
| 107 | * Returns zero on success, else an error. |
| 108 | */ |
Guennadi Liakhovetski | 5aa7dad | 2012-05-01 16:59:38 +0200 | [diff] [blame] | 109 | int mmc_gpio_request_ro(struct mmc_host *host, unsigned int gpio) |
| 110 | { |
| 111 | struct mmc_gpio *ctx; |
| 112 | int ret; |
| 113 | |
| 114 | if (!gpio_is_valid(gpio)) |
| 115 | return -EINVAL; |
| 116 | |
| 117 | ret = mmc_gpio_alloc(host); |
| 118 | if (ret < 0) |
| 119 | return ret; |
| 120 | |
| 121 | ctx = host->slot.handler_priv; |
| 122 | |
Shawn Guo | d65b5ae | 2012-12-11 22:32:18 +0800 | [diff] [blame] | 123 | ret = devm_gpio_request_one(&host->class_dev, gpio, GPIOF_DIR_IN, |
| 124 | ctx->ro_label); |
Chris Ball | 15e8a8e | 2012-09-09 22:56:48 -0400 | [diff] [blame] | 125 | if (ret < 0) |
| 126 | return ret; |
| 127 | |
| 128 | ctx->ro_gpio = gpio; |
| 129 | |
| 130 | return 0; |
Guennadi Liakhovetski | 5aa7dad | 2012-05-01 16:59:38 +0200 | [diff] [blame] | 131 | } |
| 132 | EXPORT_SYMBOL(mmc_gpio_request_ro); |
| 133 | |
Shawn Guo | d65b5ae | 2012-12-11 22:32:18 +0800 | [diff] [blame] | 134 | /** |
| 135 | * mmc_gpio_request_cd - request a gpio for card-detection |
| 136 | * @host: mmc host |
| 137 | * @gpio: gpio number requested |
Laurent Pinchart | 214fc30 | 2013-08-08 12:38:31 +0200 | [diff] [blame^] | 138 | * @debounce: debounce time in microseconds |
Shawn Guo | d65b5ae | 2012-12-11 22:32:18 +0800 | [diff] [blame] | 139 | * |
| 140 | * As devm_* managed functions are used in mmc_gpio_request_cd(), client |
| 141 | * drivers do not need to explicitly call mmc_gpio_free_cd() for freeing up, |
| 142 | * if the requesting and freeing are only needed at probing and unbinding time |
| 143 | * for once. However, if client drivers do something special like runtime |
| 144 | * switching for card-detection, they are responsible for calling |
| 145 | * mmc_gpio_request_cd() and mmc_gpio_free_cd() as a pair on their own. |
| 146 | * |
Laurent Pinchart | 214fc30 | 2013-08-08 12:38:31 +0200 | [diff] [blame^] | 147 | * If GPIO debouncing is desired, set the debounce parameter to a non-zero |
| 148 | * value. The caller is responsible for ensuring that the GPIO driver associated |
| 149 | * with the GPIO supports debouncing, otherwise an error will be returned. |
| 150 | * |
Shawn Guo | d65b5ae | 2012-12-11 22:32:18 +0800 | [diff] [blame] | 151 | * Returns zero on success, else an error. |
| 152 | */ |
Laurent Pinchart | 214fc30 | 2013-08-08 12:38:31 +0200 | [diff] [blame^] | 153 | int mmc_gpio_request_cd(struct mmc_host *host, unsigned int gpio, |
| 154 | unsigned int debounce) |
Guennadi Liakhovetski | fd0ea65 | 2012-04-30 23:31:57 +0200 | [diff] [blame] | 155 | { |
Guennadi Liakhovetski | fd0ea65 | 2012-04-30 23:31:57 +0200 | [diff] [blame] | 156 | struct mmc_gpio *ctx; |
| 157 | int irq = gpio_to_irq(gpio); |
| 158 | int ret; |
| 159 | |
Guennadi Liakhovetski | a7d1a1e | 2012-05-01 16:51:38 +0200 | [diff] [blame] | 160 | ret = mmc_gpio_alloc(host); |
| 161 | if (ret < 0) |
| 162 | return ret; |
Guennadi Liakhovetski | fd0ea65 | 2012-04-30 23:31:57 +0200 | [diff] [blame] | 163 | |
Guennadi Liakhovetski | a7d1a1e | 2012-05-01 16:51:38 +0200 | [diff] [blame] | 164 | ctx = host->slot.handler_priv; |
Guennadi Liakhovetski | fd0ea65 | 2012-04-30 23:31:57 +0200 | [diff] [blame] | 165 | |
Shawn Guo | d65b5ae | 2012-12-11 22:32:18 +0800 | [diff] [blame] | 166 | ret = devm_gpio_request_one(&host->class_dev, gpio, GPIOF_DIR_IN, |
| 167 | ctx->cd_label); |
Guennadi Liakhovetski | fd0ea65 | 2012-04-30 23:31:57 +0200 | [diff] [blame] | 168 | if (ret < 0) |
Guennadi Liakhovetski | a7d1a1e | 2012-05-01 16:51:38 +0200 | [diff] [blame] | 169 | /* |
| 170 | * don't bother freeing memory. It might still get used by other |
| 171 | * slot functions, in any case it will be freed, when the device |
| 172 | * is destroyed. |
| 173 | */ |
| 174 | return ret; |
Guennadi Liakhovetski | fd0ea65 | 2012-04-30 23:31:57 +0200 | [diff] [blame] | 175 | |
Laurent Pinchart | 214fc30 | 2013-08-08 12:38:31 +0200 | [diff] [blame^] | 176 | if (debounce) { |
| 177 | ret = gpio_set_debounce(gpio, debounce); |
| 178 | if (ret < 0) |
| 179 | return ret; |
| 180 | } |
| 181 | |
Guennadi Liakhovetski | befe404 | 2012-05-01 16:27:25 +0200 | [diff] [blame] | 182 | /* |
| 183 | * Even if gpio_to_irq() returns a valid IRQ number, the platform might |
| 184 | * still prefer to poll, e.g., because that IRQ number is already used |
| 185 | * by another unit and cannot be shared. |
| 186 | */ |
| 187 | if (irq >= 0 && host->caps & MMC_CAP_NEEDS_POLL) |
| 188 | irq = -EINVAL; |
| 189 | |
| 190 | if (irq >= 0) { |
Shawn Guo | d65b5ae | 2012-12-11 22:32:18 +0800 | [diff] [blame] | 191 | ret = devm_request_threaded_irq(&host->class_dev, irq, |
| 192 | NULL, mmc_gpio_cd_irqt, |
Guennadi Liakhovetski | fd0ea65 | 2012-04-30 23:31:57 +0200 | [diff] [blame] | 193 | IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT, |
| 194 | ctx->cd_label, host); |
Guennadi Liakhovetski | befe404 | 2012-05-01 16:27:25 +0200 | [diff] [blame] | 195 | if (ret < 0) |
| 196 | irq = ret; |
| 197 | } |
| 198 | |
| 199 | host->slot.cd_irq = irq; |
| 200 | |
| 201 | if (irq < 0) |
| 202 | host->caps |= MMC_CAP_NEEDS_POLL; |
Guennadi Liakhovetski | fd0ea65 | 2012-04-30 23:31:57 +0200 | [diff] [blame] | 203 | |
| 204 | ctx->cd_gpio = gpio; |
Guennadi Liakhovetski | fd0ea65 | 2012-04-30 23:31:57 +0200 | [diff] [blame] | 205 | |
| 206 | return 0; |
Guennadi Liakhovetski | fd0ea65 | 2012-04-30 23:31:57 +0200 | [diff] [blame] | 207 | } |
| 208 | EXPORT_SYMBOL(mmc_gpio_request_cd); |
| 209 | |
Shawn Guo | d65b5ae | 2012-12-11 22:32:18 +0800 | [diff] [blame] | 210 | /** |
| 211 | * mmc_gpio_free_ro - free the write-protection gpio |
| 212 | * @host: mmc host |
| 213 | * |
| 214 | * It's provided only for cases that client drivers need to manually free |
| 215 | * up the write-protection gpio requested by mmc_gpio_request_ro(). |
| 216 | */ |
Guennadi Liakhovetski | 5aa7dad | 2012-05-01 16:59:38 +0200 | [diff] [blame] | 217 | void mmc_gpio_free_ro(struct mmc_host *host) |
| 218 | { |
| 219 | struct mmc_gpio *ctx = host->slot.handler_priv; |
| 220 | int gpio; |
| 221 | |
| 222 | if (!ctx || !gpio_is_valid(ctx->ro_gpio)) |
| 223 | return; |
| 224 | |
| 225 | gpio = ctx->ro_gpio; |
| 226 | ctx->ro_gpio = -EINVAL; |
| 227 | |
Shawn Guo | d65b5ae | 2012-12-11 22:32:18 +0800 | [diff] [blame] | 228 | devm_gpio_free(&host->class_dev, gpio); |
Guennadi Liakhovetski | 5aa7dad | 2012-05-01 16:59:38 +0200 | [diff] [blame] | 229 | } |
| 230 | EXPORT_SYMBOL(mmc_gpio_free_ro); |
| 231 | |
Shawn Guo | d65b5ae | 2012-12-11 22:32:18 +0800 | [diff] [blame] | 232 | /** |
| 233 | * mmc_gpio_free_cd - free the card-detection gpio |
| 234 | * @host: mmc host |
| 235 | * |
| 236 | * It's provided only for cases that client drivers need to manually free |
| 237 | * up the card-detection gpio requested by mmc_gpio_request_cd(). |
| 238 | */ |
Guennadi Liakhovetski | fd0ea65 | 2012-04-30 23:31:57 +0200 | [diff] [blame] | 239 | void mmc_gpio_free_cd(struct mmc_host *host) |
| 240 | { |
Guennadi Liakhovetski | 27410ee | 2012-05-01 15:40:15 +0200 | [diff] [blame] | 241 | struct mmc_gpio *ctx = host->slot.handler_priv; |
Guennadi Liakhovetski | befe404 | 2012-05-01 16:27:25 +0200 | [diff] [blame] | 242 | int gpio; |
Guennadi Liakhovetski | fd0ea65 | 2012-04-30 23:31:57 +0200 | [diff] [blame] | 243 | |
Guennadi Liakhovetski | befe404 | 2012-05-01 16:27:25 +0200 | [diff] [blame] | 244 | if (!ctx || !gpio_is_valid(ctx->cd_gpio)) |
Guennadi Liakhovetski | fd0ea65 | 2012-04-30 23:31:57 +0200 | [diff] [blame] | 245 | return; |
| 246 | |
Guennadi Liakhovetski | befe404 | 2012-05-01 16:27:25 +0200 | [diff] [blame] | 247 | if (host->slot.cd_irq >= 0) { |
Shawn Guo | d65b5ae | 2012-12-11 22:32:18 +0800 | [diff] [blame] | 248 | devm_free_irq(&host->class_dev, host->slot.cd_irq, host); |
Guennadi Liakhovetski | befe404 | 2012-05-01 16:27:25 +0200 | [diff] [blame] | 249 | host->slot.cd_irq = -EINVAL; |
| 250 | } |
| 251 | |
| 252 | gpio = ctx->cd_gpio; |
| 253 | ctx->cd_gpio = -EINVAL; |
| 254 | |
Shawn Guo | d65b5ae | 2012-12-11 22:32:18 +0800 | [diff] [blame] | 255 | devm_gpio_free(&host->class_dev, gpio); |
Guennadi Liakhovetski | fd0ea65 | 2012-04-30 23:31:57 +0200 | [diff] [blame] | 256 | } |
| 257 | EXPORT_SYMBOL(mmc_gpio_free_cd); |