| /* |
| * linux/drivers/mmc/core/sdio_irq.c |
| * |
| * Author: Nicolas Pitre |
| * Created: June 18, 2007 |
| * Copyright: MontaVista Software Inc. |
| * |
| * Copyright 2008 Pierre Ossman |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or (at |
| * your option) any later version. |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/sched.h> |
| #include <linux/kthread.h> |
| #include <linux/wait.h> |
| #include <linux/delay.h> |
| |
| #include <linux/mmc/core.h> |
| #include <linux/mmc/host.h> |
| #include <linux/mmc/card.h> |
| #include <linux/mmc/sdio.h> |
| #include <linux/mmc/sdio_func.h> |
| |
| #include "sdio_ops.h" |
| |
| static int process_sdio_pending_irqs(struct mmc_host *host) |
| { |
| struct mmc_card *card = host->card; |
| int i, ret, count; |
| unsigned char pending; |
| struct sdio_func *func; |
| |
| /* |
| * Optimization, if there is only 1 function interrupt registered |
| * and we know an IRQ was signaled then call irq handler directly. |
| * Otherwise do the full probe. |
| */ |
| func = card->sdio_single_irq; |
| if (func && host->sdio_irq_pending) { |
| func->irq_handler(func); |
| return 1; |
| } |
| |
| ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, &pending); |
| if (ret) { |
| printk(KERN_DEBUG "%s: error %d reading SDIO_CCCR_INTx\n", |
| mmc_card_id(card), ret); |
| return ret; |
| } |
| |
| count = 0; |
| for (i = 1; i <= 7; i++) { |
| if (pending & (1 << i)) { |
| func = card->sdio_func[i - 1]; |
| if (!func) { |
| printk(KERN_WARNING "%s: pending IRQ for " |
| "non-existent function\n", |
| mmc_card_id(card)); |
| ret = -EINVAL; |
| } else if (func->irq_handler) { |
| func->irq_handler(func); |
| count++; |
| } else { |
| printk(KERN_WARNING "%s: pending IRQ with no handler\n", |
| sdio_func_id(func)); |
| ret = -EINVAL; |
| } |
| } |
| } |
| |
| if (count) |
| return count; |
| |
| return ret; |
| } |
| |
| static int sdio_irq_thread(void *_host) |
| { |
| struct mmc_host *host = _host; |
| struct sched_param param = { .sched_priority = 1 }; |
| unsigned long period, idle_period; |
| int ret; |
| |
| sched_setscheduler(current, SCHED_FIFO, ¶m); |
| |
| /* |
| * We want to allow for SDIO cards to work even on non SDIO |
| * aware hosts. One thing that non SDIO host cannot do is |
| * asynchronous notification of pending SDIO card interrupts |
| * hence we poll for them in that case. |
| */ |
| idle_period = msecs_to_jiffies(10); |
| period = (host->caps & MMC_CAP_SDIO_IRQ) ? |
| MAX_SCHEDULE_TIMEOUT : idle_period; |
| |
| pr_debug("%s: IRQ thread started (poll period = %lu jiffies)\n", |
| mmc_hostname(host), period); |
| |
| do { |
| /* |
| * We claim the host here on drivers behalf for a couple |
| * reasons: |
| * |
| * 1) it is already needed to retrieve the CCCR_INTx; |
| * 2) we want the driver(s) to clear the IRQ condition ASAP; |
| * 3) we need to control the abort condition locally. |
| * |
| * Just like traditional hard IRQ handlers, we expect SDIO |
| * IRQ handlers to be quick and to the point, so that the |
| * holding of the host lock does not cover too much work |
| * that doesn't require that lock to be held. |
| */ |
| ret = __mmc_claim_host(host, &host->sdio_irq_thread_abort); |
| if (ret) |
| break; |
| ret = process_sdio_pending_irqs(host); |
| host->sdio_irq_pending = false; |
| mmc_release_host(host); |
| |
| /* |
| * Give other threads a chance to run in the presence of |
| * errors. |
| */ |
| if (ret < 0) { |
| set_current_state(TASK_INTERRUPTIBLE); |
| if (!kthread_should_stop()) |
| schedule_timeout(HZ); |
| set_current_state(TASK_RUNNING); |
| } |
| |
| /* |
| * Adaptive polling frequency based on the assumption |
| * that an interrupt will be closely followed by more. |
| * This has a substantial benefit for network devices. |
| */ |
| if (!(host->caps & MMC_CAP_SDIO_IRQ)) { |
| if (ret > 0) |
| period /= 2; |
| else { |
| period++; |
| if (period > idle_period) |
| period = idle_period; |
| } |
| } |
| |
| set_current_state(TASK_INTERRUPTIBLE); |
| if (host->caps & MMC_CAP_SDIO_IRQ) { |
| mmc_host_clk_hold(host); |
| host->ops->enable_sdio_irq(host, 1); |
| mmc_host_clk_release(host); |
| } |
| if (!kthread_should_stop()) |
| schedule_timeout(period); |
| set_current_state(TASK_RUNNING); |
| } while (!kthread_should_stop()); |
| |
| if (host->caps & MMC_CAP_SDIO_IRQ) { |
| mmc_host_clk_hold(host); |
| host->ops->enable_sdio_irq(host, 0); |
| mmc_host_clk_release(host); |
| } |
| |
| pr_debug("%s: IRQ thread exiting with code %d\n", |
| mmc_hostname(host), ret); |
| |
| return ret; |
| } |
| |
| static int sdio_card_irq_get(struct mmc_card *card) |
| { |
| struct mmc_host *host = card->host; |
| |
| WARN_ON(!host->claimed); |
| |
| if (!host->sdio_irqs++) { |
| atomic_set(&host->sdio_irq_thread_abort, 0); |
| host->sdio_irq_thread = |
| kthread_run(sdio_irq_thread, host, "ksdioirqd/%s", |
| mmc_hostname(host)); |
| if (IS_ERR(host->sdio_irq_thread)) { |
| int err = PTR_ERR(host->sdio_irq_thread); |
| host->sdio_irqs--; |
| return err; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int sdio_card_irq_put(struct mmc_card *card) |
| { |
| struct mmc_host *host = card->host; |
| |
| WARN_ON(!host->claimed); |
| BUG_ON(host->sdio_irqs < 1); |
| |
| if (!--host->sdio_irqs) { |
| atomic_set(&host->sdio_irq_thread_abort, 1); |
| kthread_stop(host->sdio_irq_thread); |
| } |
| |
| return 0; |
| } |
| |
| /* If there is only 1 function registered set sdio_single_irq */ |
| static void sdio_single_irq_set(struct mmc_card *card) |
| { |
| struct sdio_func *func; |
| int i; |
| |
| card->sdio_single_irq = NULL; |
| if ((card->host->caps & MMC_CAP_SDIO_IRQ) && |
| card->host->sdio_irqs == 1) |
| for (i = 0; i < card->sdio_funcs; i++) { |
| func = card->sdio_func[i]; |
| if (func && func->irq_handler) { |
| card->sdio_single_irq = func; |
| break; |
| } |
| } |
| } |
| |
| /** |
| * sdio_claim_irq - claim the IRQ for a SDIO function |
| * @func: SDIO function |
| * @handler: IRQ handler callback |
| * |
| * Claim and activate the IRQ for the given SDIO function. The provided |
| * handler will be called when that IRQ is asserted. The host is always |
| * claimed already when the handler is called so the handler must not |
| * call sdio_claim_host() nor sdio_release_host(). |
| */ |
| int sdio_claim_irq(struct sdio_func *func, sdio_irq_handler_t *handler) |
| { |
| int ret; |
| unsigned char reg; |
| |
| BUG_ON(!func); |
| BUG_ON(!func->card); |
| |
| pr_debug("SDIO: Enabling IRQ for %s...\n", sdio_func_id(func)); |
| |
| if (func->irq_handler) { |
| pr_debug("SDIO: IRQ for %s already in use.\n", sdio_func_id(func)); |
| return -EBUSY; |
| } |
| |
| ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®); |
| if (ret) |
| return ret; |
| |
| reg |= 1 << func->num; |
| |
| reg |= 1; /* Master interrupt enable */ |
| |
| ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL); |
| if (ret) |
| return ret; |
| |
| func->irq_handler = handler; |
| ret = sdio_card_irq_get(func->card); |
| if (ret) |
| func->irq_handler = NULL; |
| sdio_single_irq_set(func->card); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(sdio_claim_irq); |
| |
| /** |
| * sdio_release_irq - release the IRQ for a SDIO function |
| * @func: SDIO function |
| * |
| * Disable and release the IRQ for the given SDIO function. |
| */ |
| int sdio_release_irq(struct sdio_func *func) |
| { |
| int ret; |
| unsigned char reg; |
| |
| BUG_ON(!func); |
| BUG_ON(!func->card); |
| |
| pr_debug("SDIO: Disabling IRQ for %s...\n", sdio_func_id(func)); |
| |
| if (func->irq_handler) { |
| func->irq_handler = NULL; |
| sdio_card_irq_put(func->card); |
| sdio_single_irq_set(func->card); |
| } |
| |
| ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®); |
| if (ret) |
| return ret; |
| |
| reg &= ~(1 << func->num); |
| |
| /* Disable master interrupt with the last function interrupt */ |
| if (!(reg & 0xFE)) |
| reg = 0; |
| |
| ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL); |
| if (ret) |
| return ret; |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(sdio_release_irq); |
| |