--- /dev/null
+/*
+ * 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/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"
+
+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);
+
Code Review / kvmfornfv.git / blobdiff