Nicolas Pitre | d1496c3 | 2007-06-30 16:29:41 +0200 | [diff] [blame^] | 1 | /* |
| 2 | * linux/drivers/mmc/core/sdio_irq.c |
| 3 | * |
| 4 | * Author: Nicolas Pitre |
| 5 | * Created: June 18, 2007 |
| 6 | * Copyright: MontaVista Software Inc. |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License as published by |
| 10 | * the Free Software Foundation; either version 2 of the License, or (at |
| 11 | * your option) any later version. |
| 12 | */ |
| 13 | |
| 14 | #include <linux/kernel.h> |
| 15 | #include <linux/sched.h> |
| 16 | #include <linux/kthread.h> |
| 17 | #include <linux/wait.h> |
| 18 | #include <linux/delay.h> |
| 19 | |
| 20 | #include <linux/mmc/core.h> |
| 21 | #include <linux/mmc/host.h> |
| 22 | #include <linux/mmc/card.h> |
| 23 | #include <linux/mmc/sdio.h> |
| 24 | #include <linux/mmc/sdio_func.h> |
| 25 | |
| 26 | #include "sdio_ops.h" |
| 27 | |
| 28 | static int process_sdio_pending_irqs(struct mmc_card *card) |
| 29 | { |
| 30 | int i, ret; |
| 31 | unsigned char pending; |
| 32 | |
| 33 | ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, &pending); |
| 34 | if (ret) { |
| 35 | printk(KERN_DEBUG "%s: error %d reading SDIO_CCCR_INTx\n", |
| 36 | mmc_card_id(card), ret); |
| 37 | return ret; |
| 38 | } |
| 39 | |
| 40 | for (i = 1; i <= 7; i++) { |
| 41 | if (pending & (1 << i)) { |
| 42 | struct sdio_func *func = card->sdio_func[i - 1]; |
| 43 | if (!func) { |
| 44 | printk(KERN_WARNING "%s: pending IRQ for " |
| 45 | "non-existant function\n", |
| 46 | sdio_func_id(func)); |
| 47 | } else if (func->irq_handler) { |
| 48 | func->irq_handler(func); |
| 49 | } else |
| 50 | printk(KERN_WARNING "%s: pending IRQ with no handler\n", |
| 51 | sdio_func_id(func)); |
| 52 | } |
| 53 | } |
| 54 | |
| 55 | return 0; |
| 56 | } |
| 57 | |
| 58 | static int sdio_irq_thread(void *_host) |
| 59 | { |
| 60 | struct mmc_host *host = _host; |
| 61 | struct sched_param param = { .sched_priority = 1 }; |
| 62 | unsigned long period; |
| 63 | int ret; |
| 64 | |
| 65 | sched_setscheduler(current, SCHED_FIFO, ¶m); |
| 66 | |
| 67 | /* |
| 68 | * We want to allow for SDIO cards to work even on non SDIO |
| 69 | * aware hosts. One thing that non SDIO host cannot do is |
| 70 | * asynchronous notification of pending SDIO card interrupts |
| 71 | * hence we poll for them in that case. |
| 72 | */ |
| 73 | period = msecs_to_jiffies(10); |
| 74 | |
| 75 | pr_debug("%s: IRQ thread started (poll period = %lu jiffies)\n", |
| 76 | mmc_hostname(host), period); |
| 77 | |
| 78 | do { |
| 79 | /* |
| 80 | * We claim the host here on drivers behalf for a couple |
| 81 | * reasons: |
| 82 | * |
| 83 | * 1) it is already needed to retrieve the CCCR_INTx; |
| 84 | * 2) we want the driver(s) to clear the IRQ condition ASAP; |
| 85 | * 3) we need to control the abort condition locally. |
| 86 | * |
| 87 | * Just like traditional hard IRQ handlers, we expect SDIO |
| 88 | * IRQ handlers to be quick and to the point, so that the |
| 89 | * holding of the host lock does not cover too much work |
| 90 | * that doesn't require that lock to be held. |
| 91 | */ |
| 92 | ret = __mmc_claim_host(host, &host->sdio_irq_thread_abort); |
| 93 | if (ret) |
| 94 | break; |
| 95 | ret = process_sdio_pending_irqs(host->card); |
| 96 | mmc_release_host(host); |
| 97 | |
| 98 | /* |
| 99 | * Give other threads a chance to run in the presence of |
| 100 | * errors. FIXME: determine if due to card removal and |
| 101 | * possibly exit this thread if so. |
| 102 | */ |
| 103 | if (ret) |
| 104 | ssleep(1); |
| 105 | |
| 106 | set_task_state(current, TASK_INTERRUPTIBLE); |
| 107 | if (!kthread_should_stop()) |
| 108 | schedule_timeout(period); |
| 109 | set_task_state(current, TASK_RUNNING); |
| 110 | } while (!kthread_should_stop()); |
| 111 | |
| 112 | pr_debug("%s: IRQ thread exiting with code %d\n", |
| 113 | mmc_hostname(host), ret); |
| 114 | |
| 115 | return ret; |
| 116 | } |
| 117 | |
| 118 | static int sdio_card_irq_get(struct mmc_card *card) |
| 119 | { |
| 120 | struct mmc_host *host = card->host; |
| 121 | |
| 122 | BUG_ON(!host->claimed); |
| 123 | |
| 124 | if (!host->sdio_irqs++) { |
| 125 | atomic_set(&host->sdio_irq_thread_abort, 0); |
| 126 | host->sdio_irq_thread = |
| 127 | kthread_run(sdio_irq_thread, host, "ksdiorqd"); |
| 128 | if (IS_ERR(host->sdio_irq_thread)) { |
| 129 | int err = PTR_ERR(host->sdio_irq_thread); |
| 130 | host->sdio_irqs--; |
| 131 | return err; |
| 132 | } |
| 133 | } |
| 134 | |
| 135 | return 0; |
| 136 | } |
| 137 | |
| 138 | static int sdio_card_irq_put(struct mmc_card *card) |
| 139 | { |
| 140 | struct mmc_host *host = card->host; |
| 141 | |
| 142 | BUG_ON(!host->claimed); |
| 143 | BUG_ON(host->sdio_irqs < 1); |
| 144 | |
| 145 | if (!--host->sdio_irqs) { |
| 146 | atomic_set(&host->sdio_irq_thread_abort, 1); |
| 147 | kthread_stop(host->sdio_irq_thread); |
| 148 | } |
| 149 | |
| 150 | return 0; |
| 151 | } |
| 152 | |
| 153 | /** |
| 154 | * sdio_claim_irq - claim the IRQ for a SDIO function |
| 155 | * @func: SDIO function |
| 156 | * @handler: IRQ handler callback |
| 157 | * |
| 158 | * Claim and activate the IRQ for the given SDIO function. The provided |
| 159 | * handler will be called when that IRQ is asserted. The host is always |
| 160 | * claimed already when the handler is called so the handler must not |
| 161 | * call sdio_claim_host() nor sdio_release_host(). |
| 162 | */ |
| 163 | int sdio_claim_irq(struct sdio_func *func, sdio_irq_handler_t *handler) |
| 164 | { |
| 165 | int ret; |
| 166 | unsigned char reg; |
| 167 | |
| 168 | BUG_ON(!func); |
| 169 | BUG_ON(!func->card); |
| 170 | |
| 171 | pr_debug("SDIO: Enabling IRQ for %s...\n", sdio_func_id(func)); |
| 172 | |
| 173 | if (func->irq_handler) { |
| 174 | pr_debug("SDIO: IRQ for %s already in use.\n", sdio_func_id(func)); |
| 175 | return -EBUSY; |
| 176 | } |
| 177 | |
| 178 | ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®); |
| 179 | if (ret) |
| 180 | return ret; |
| 181 | |
| 182 | reg |= 1 << func->num; |
| 183 | |
| 184 | reg |= 1; /* Master interrupt enable */ |
| 185 | |
| 186 | ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL); |
| 187 | if (ret) |
| 188 | return ret; |
| 189 | |
| 190 | func->irq_handler = handler; |
| 191 | ret = sdio_card_irq_get(func->card); |
| 192 | if (ret) |
| 193 | func->irq_handler = NULL; |
| 194 | |
| 195 | return ret; |
| 196 | } |
| 197 | EXPORT_SYMBOL_GPL(sdio_claim_irq); |
| 198 | |
| 199 | /** |
| 200 | * sdio_release_irq - release the IRQ for a SDIO function |
| 201 | * @func: SDIO function |
| 202 | * |
| 203 | * Disable and release the IRQ for the given SDIO function. |
| 204 | */ |
| 205 | int sdio_release_irq(struct sdio_func *func) |
| 206 | { |
| 207 | int ret; |
| 208 | unsigned char reg; |
| 209 | |
| 210 | BUG_ON(!func); |
| 211 | BUG_ON(!func->card); |
| 212 | |
| 213 | pr_debug("SDIO: Disabling IRQ for %s...\n", sdio_func_id(func)); |
| 214 | |
| 215 | if (func->irq_handler) { |
| 216 | func->irq_handler = NULL; |
| 217 | sdio_card_irq_put(func->card); |
| 218 | } |
| 219 | |
| 220 | ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®); |
| 221 | if (ret) |
| 222 | return ret; |
| 223 | |
| 224 | reg &= ~(1 << func->num); |
| 225 | |
| 226 | /* Disable master interrupt with the last function interrupt */ |
| 227 | if (!(reg & 0xFE)) |
| 228 | reg = 0; |
| 229 | |
| 230 | ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL); |
| 231 | if (ret) |
| 232 | return ret; |
| 233 | |
| 234 | return 0; |
| 235 | } |
| 236 | EXPORT_SYMBOL_GPL(sdio_release_irq); |
| 237 | |