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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/mmc/core/sdio_irq.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/mmc/core/sdio_irq.c')
-rw-r--r-- | drivers/mmc/core/sdio_irq.c | 375 |
1 files changed, 375 insertions, 0 deletions
diff --git a/drivers/mmc/core/sdio_irq.c b/drivers/mmc/core/sdio_irq.c new file mode 100644 index 000000000..2b24bdf38 --- /dev/null +++ b/drivers/mmc/core/sdio_irq.c @@ -0,0 +1,375 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * linux/drivers/mmc/core/sdio_irq.c + * + * Author: Nicolas Pitre + * Created: June 18, 2007 + * Copyright: MontaVista Software Inc. + * + * Copyright 2008 Pierre Ossman + */ + +#include <linux/kernel.h> +#include <linux/sched.h> +#include <uapi/linux/sched/types.h> +#include <linux/kthread.h> +#include <linux/export.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" +#include "core.h" +#include "card.h" + +static int sdio_get_pending_irqs(struct mmc_host *host, u8 *pending) +{ + struct mmc_card *card = host->card; + int ret; + + WARN_ON(!host->claimed); + + 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); + } + + return 0; +} + +static int process_sdio_pending_irqs(struct mmc_host *host) +{ + struct mmc_card *card = host->card; + int i, ret, count; + bool sdio_irq_pending = host->sdio_irq_pending; + unsigned char pending; + struct sdio_func *func; + + /* Don't process SDIO IRQs if the card is suspended. */ + if (mmc_card_suspended(card)) + return 0; + + /* Clear the flag to indicate that we have processed the IRQ. */ + host->sdio_irq_pending = false; + + /* + * 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 && sdio_irq_pending) { + func->irq_handler(func); + return 1; + } + + ret = sdio_get_pending_irqs(host, &pending); + if (ret) + return ret; + + 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; +} + +static void sdio_run_irqs(struct mmc_host *host) +{ + mmc_claim_host(host); + if (host->sdio_irqs) { + process_sdio_pending_irqs(host); + if (!host->sdio_irq_pending) + host->ops->ack_sdio_irq(host); + } + mmc_release_host(host); +} + +void sdio_irq_work(struct work_struct *work) +{ + struct mmc_host *host = + container_of(work, struct mmc_host, sdio_irq_work); + + sdio_run_irqs(host); +} + +void sdio_signal_irq(struct mmc_host *host) +{ + host->sdio_irq_pending = true; + schedule_work(&host->sdio_irq_work); +} +EXPORT_SYMBOL_GPL(sdio_signal_irq); + +static int sdio_irq_thread(void *_host) +{ + struct mmc_host *host = _host; + unsigned long period, idle_period; + int ret; + + sched_set_fifo_low(current); + + /* + * 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, NULL, + &host->sdio_irq_thread_abort); + if (ret) + break; + ret = process_sdio_pending_irqs(host); + 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) + host->ops->enable_sdio_irq(host, 1); + if (!kthread_should_stop()) + schedule_timeout(period); + set_current_state(TASK_RUNNING); + } while (!kthread_should_stop()); + + if (host->caps & MMC_CAP_SDIO_IRQ) + host->ops->enable_sdio_irq(host, 0); + + 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) { + host->ops->enable_sdio_irq(host, 1); + } + } + + return 0; +} + +static int sdio_card_irq_put(struct mmc_card *card) +{ + struct mmc_host *host = card->host; + + WARN_ON(!host->claimed); + + if (host->sdio_irqs < 1) + return -EINVAL; + + 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) { + host->ops->enable_sdio_irq(host, 0); + } + } + + 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 should not + * call sdio_claim_host() or sdio_release_host(). + */ +int sdio_claim_irq(struct sdio_func *func, sdio_irq_handler_t *handler) +{ + int ret; + unsigned char reg; + + if (!func) + return -EINVAL; + + 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; + + if (!func) + return -EINVAL; + + 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); + |