From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: AndrĂ© Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- drivers/mmc/core/sdio_irq.c | 345 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 345 insertions(+) create mode 100644 drivers/mmc/core/sdio_irq.c (limited to 'drivers/mmc/core/sdio_irq.c') diff --git a/drivers/mmc/core/sdio_irq.c b/drivers/mmc/core/sdio_irq.c new file mode 100644 index 000000000..09cc67d02 --- /dev/null +++ b/drivers/mmc/core/sdio_irq.c @@ -0,0 +1,345 @@ +/* + * 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 +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include + +#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) { + pr_debug("%s: error %d reading SDIO_CCCR_INTx\n", + mmc_card_id(card), ret); + return ret; + } + + if (pending && mmc_card_broken_irq_polling(card) && + !(host->caps & MMC_CAP_SDIO_IRQ)) { + unsigned char dummy; + + /* A fake interrupt could be created when we poll SDIO_CCCR_INTx + * register with a Marvell SD8797 card. A dummy CMD52 read to + * function 0 register 0xff can avoid this. + */ + mmc_io_rw_direct(card, 0, 0, 0xff, 0, &dummy); + } + + count = 0; + for (i = 1; i <= 7; i++) { + if (pending & (1 << i)) { + func = card->sdio_func[i - 1]; + if (!func) { + pr_warn("%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 { + pr_warn("%s: pending IRQ with no handler\n", + sdio_func_id(func)); + ret = -EINVAL; + } + } + } + + if (count) + return count; + + return ret; +} + +void sdio_run_irqs(struct mmc_host *host) +{ + mmc_claim_host(host); + host->sdio_irq_pending = true; + process_sdio_pending_irqs(host); + mmc_release_host(host); +} +EXPORT_SYMBOL_GPL(sdio_run_irqs); + +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++) { + if (!(host->caps2 & MMC_CAP2_SDIO_IRQ_NOTHREAD)) { + 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; + } + } else if (host->caps & MMC_CAP_SDIO_IRQ) { + mmc_host_clk_hold(host); + host->ops->enable_sdio_irq(host, 1); + mmc_host_clk_release(host); + } + } + + 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) { + if (!(host->caps2 & MMC_CAP2_SDIO_IRQ_NOTHREAD)) { + atomic_set(&host->sdio_irq_thread_abort, 1); + kthread_stop(host->sdio_irq_thread); + } else if (host->caps & MMC_CAP_SDIO_IRQ) { + mmc_host_clk_hold(host); + host->ops->enable_sdio_irq(host, 0); + mmc_host_clk_release(host); + } + } + + 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); + -- cgit v1.2.3-54-g00ecf