diff options
| -rw-r--r-- | drivers/mmc/core/Makefile | 2 | ||||
| -rw-r--r-- | drivers/mmc/core/sdio_bus.c | 8 | ||||
| -rw-r--r-- | drivers/mmc/core/sdio_irq.c | 237 | ||||
| -rw-r--r-- | include/linux/mmc/host.h | 4 | ||||
| -rw-r--r-- | include/linux/mmc/sdio_func.h | 7 |
5 files changed, 257 insertions, 1 deletions
diff --git a/drivers/mmc/core/Makefile b/drivers/mmc/core/Makefile index 05d69fc72c1..4985807257a 100644 --- a/drivers/mmc/core/Makefile +++ b/drivers/mmc/core/Makefile @@ -10,5 +10,5 @@ obj-$(CONFIG_MMC) += mmc_core.o mmc_core-y := core.o sysfs.o bus.o host.o \ mmc.o mmc_ops.o sd.o sd_ops.o \ sdio.o sdio_ops.o sdio_bus.o \ - sdio_cis.o sdio_io.o + sdio_cis.o sdio_io.o sdio_irq.o diff --git a/drivers/mmc/core/sdio_bus.c b/drivers/mmc/core/sdio_bus.c index 129f0719c39..24072445491 100644 --- a/drivers/mmc/core/sdio_bus.c +++ b/drivers/mmc/core/sdio_bus.c @@ -143,6 +143,14 @@ static int sdio_bus_remove(struct device *dev) drv->remove(func); + if (func->irq_handler) { + printk(KERN_WARNING "WARNING: driver %s did not remove " + "its interrupt handler!\n", drv->name); + sdio_claim_host(func); + sdio_release_irq(func); + sdio_release_host(func); + } + return 0; } diff --git a/drivers/mmc/core/sdio_irq.c b/drivers/mmc/core/sdio_irq.c new file mode 100644 index 00000000000..01922d29241 --- /dev/null +++ b/drivers/mmc/core/sdio_irq.c @@ -0,0 +1,237 @@ +/* + * linux/drivers/mmc/core/sdio_irq.c + * + * Author: Nicolas Pitre + * Created: June 18, 2007 + * Copyright: MontaVista Software Inc. + * + * 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_card *card) +{ + int i, ret; + unsigned char pending; + + 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; + } + + for (i = 1; i <= 7; i++) { + if (pending & (1 << i)) { + struct sdio_func *func = card->sdio_func[i - 1]; + if (!func) { + printk(KERN_WARNING "%s: pending IRQ for " + "non-existant function\n", + sdio_func_id(func)); + } else if (func->irq_handler) { + func->irq_handler(func); + } else + printk(KERN_WARNING "%s: pending IRQ with no handler\n", + sdio_func_id(func)); + } + } + + return 0; +} + +static int sdio_irq_thread(void *_host) +{ + struct mmc_host *host = _host; + struct sched_param param = { .sched_priority = 1 }; + unsigned long 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. + */ + period = msecs_to_jiffies(10); + + 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->card); + mmc_release_host(host); + + /* + * Give other threads a chance to run in the presence of + * errors. FIXME: determine if due to card removal and + * possibly exit this thread if so. + */ + if (ret) + ssleep(1); + + set_task_state(current, TASK_INTERRUPTIBLE); + if (!kthread_should_stop()) + schedule_timeout(period); + set_task_state(current, TASK_RUNNING); + } while (!kthread_should_stop()); + + 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; + + BUG_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, "ksdiorqd"); + 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; + + BUG_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; +} + +/** + * 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; + + 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); + } + + 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); + diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index 8e2642ebf02..00dc1809494 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -123,6 +123,10 @@ struct mmc_host { unsigned int bus_refs; /* reference counter */ unsigned int bus_dead:1; /* bus has been released */ + unsigned int sdio_irqs; + struct task_struct *sdio_irq_thread; + atomic_t sdio_irq_thread_abort; + unsigned long private[0] ____cacheline_aligned; }; diff --git a/include/linux/mmc/sdio_func.h b/include/linux/mmc/sdio_func.h index 8106d399c41..a8d268c9c27 100644 --- a/include/linux/mmc/sdio_func.h +++ b/include/linux/mmc/sdio_func.h @@ -16,6 +16,9 @@ #include <linux/mod_devicetable.h> struct mmc_card; +struct sdio_func; + +typedef void (sdio_irq_handler_t)(struct sdio_func *); /* * SDIO function CIS tuple (unknown to the core) @@ -33,6 +36,7 @@ struct sdio_func_tuple { struct sdio_func { struct mmc_card *card; /* the card this device belongs to */ struct device dev; /* the device */ + sdio_irq_handler_t *irq_handler; /* IRQ callback */ unsigned int num; /* function number */ unsigned char class; /* standard interface class */ @@ -105,6 +109,9 @@ extern void sdio_release_host(struct sdio_func *func); extern int sdio_enable_func(struct sdio_func *func); extern int sdio_disable_func(struct sdio_func *func); +extern int sdio_claim_irq(struct sdio_func *func, sdio_irq_handler_t *handler); +extern int sdio_release_irq(struct sdio_func *func); + extern unsigned char sdio_readb(struct sdio_func *func, unsigned int addr, int *err_ret); |