--- /dev/null
+/*
+ * linux/drivers/mmc/core/host.c
+ *
+ * Copyright (C) 2003 Russell King, All Rights Reserved.
+ * Copyright (C) 2007-2008 Pierre Ossman
+ * Copyright (C) 2010 Linus Walleij
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * MMC host class device management
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/idr.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/pagemap.h>
+#include <linux/export.h>
+#include <linux/leds.h>
+#include <linux/slab.h>
+#include <linux/suspend.h>
+
+#include <linux/mmc/host.h>
+#include <linux/mmc/card.h>
+#include <linux/mmc/slot-gpio.h>
+
+#include "core.h"
+#include "host.h"
+#include "slot-gpio.h"
+#include "pwrseq.h"
+
+#define cls_dev_to_mmc_host(d) container_of(d, struct mmc_host, class_dev)
+
+static DEFINE_IDR(mmc_host_idr);
+static DEFINE_SPINLOCK(mmc_host_lock);
+
+static void mmc_host_classdev_release(struct device *dev)
+{
+ struct mmc_host *host = cls_dev_to_mmc_host(dev);
+ spin_lock(&mmc_host_lock);
+ idr_remove(&mmc_host_idr, host->index);
+ spin_unlock(&mmc_host_lock);
+ kfree(host);
+}
+
+static struct class mmc_host_class = {
+ .name = "mmc_host",
+ .dev_release = mmc_host_classdev_release,
+};
+
+int mmc_register_host_class(void)
+{
+ return class_register(&mmc_host_class);
+}
+
+void mmc_unregister_host_class(void)
+{
+ class_unregister(&mmc_host_class);
+}
+
+#ifdef CONFIG_MMC_CLKGATE
+static ssize_t clkgate_delay_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct mmc_host *host = cls_dev_to_mmc_host(dev);
+ return snprintf(buf, PAGE_SIZE, "%lu\n", host->clkgate_delay);
+}
+
+static ssize_t clkgate_delay_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t count)
+{
+ struct mmc_host *host = cls_dev_to_mmc_host(dev);
+ unsigned long flags, value;
+
+ if (kstrtoul(buf, 0, &value))
+ return -EINVAL;
+
+ spin_lock_irqsave(&host->clk_lock, flags);
+ host->clkgate_delay = value;
+ spin_unlock_irqrestore(&host->clk_lock, flags);
+ return count;
+}
+
+/*
+ * Enabling clock gating will make the core call out to the host
+ * once up and once down when it performs a request or card operation
+ * intermingled in any fashion. The driver will see this through
+ * set_ios() operations with ios.clock field set to 0 to gate (disable)
+ * the block clock, and to the old frequency to enable it again.
+ */
+static void mmc_host_clk_gate_delayed(struct mmc_host *host)
+{
+ unsigned long tick_ns;
+ unsigned long freq = host->ios.clock;
+ unsigned long flags;
+
+ if (!freq) {
+ pr_debug("%s: frequency set to 0 in disable function, "
+ "this means the clock is already disabled.\n",
+ mmc_hostname(host));
+ return;
+ }
+ /*
+ * New requests may have appeared while we were scheduling,
+ * then there is no reason to delay the check before
+ * clk_disable().
+ */
+ spin_lock_irqsave(&host->clk_lock, flags);
+
+ /*
+ * Delay n bus cycles (at least 8 from MMC spec) before attempting
+ * to disable the MCI block clock. The reference count may have
+ * gone up again after this delay due to rescheduling!
+ */
+ if (!host->clk_requests) {
+ spin_unlock_irqrestore(&host->clk_lock, flags);
+ tick_ns = DIV_ROUND_UP(1000000000, freq);
+ ndelay(host->clk_delay * tick_ns);
+ } else {
+ /* New users appeared while waiting for this work */
+ spin_unlock_irqrestore(&host->clk_lock, flags);
+ return;
+ }
+ mutex_lock(&host->clk_gate_mutex);
+ spin_lock_irqsave(&host->clk_lock, flags);
+ if (!host->clk_requests) {
+ spin_unlock_irqrestore(&host->clk_lock, flags);
+ /* This will set host->ios.clock to 0 */
+ mmc_gate_clock(host);
+ spin_lock_irqsave(&host->clk_lock, flags);
+ pr_debug("%s: gated MCI clock\n", mmc_hostname(host));
+ }
+ spin_unlock_irqrestore(&host->clk_lock, flags);
+ mutex_unlock(&host->clk_gate_mutex);
+}
+
+/*
+ * Internal work. Work to disable the clock at some later point.
+ */
+static void mmc_host_clk_gate_work(struct work_struct *work)
+{
+ struct mmc_host *host = container_of(work, struct mmc_host,
+ clk_gate_work.work);
+
+ mmc_host_clk_gate_delayed(host);
+}
+
+/**
+ * mmc_host_clk_hold - ungate hardware MCI clocks
+ * @host: host to ungate.
+ *
+ * Makes sure the host ios.clock is restored to a non-zero value
+ * past this call. Increase clock reference count and ungate clock
+ * if we're the first user.
+ */
+void mmc_host_clk_hold(struct mmc_host *host)
+{
+ unsigned long flags;
+
+ /* cancel any clock gating work scheduled by mmc_host_clk_release() */
+ cancel_delayed_work_sync(&host->clk_gate_work);
+ mutex_lock(&host->clk_gate_mutex);
+ spin_lock_irqsave(&host->clk_lock, flags);
+ if (host->clk_gated) {
+ spin_unlock_irqrestore(&host->clk_lock, flags);
+ mmc_ungate_clock(host);
+ spin_lock_irqsave(&host->clk_lock, flags);
+ pr_debug("%s: ungated MCI clock\n", mmc_hostname(host));
+ }
+ host->clk_requests++;
+ spin_unlock_irqrestore(&host->clk_lock, flags);
+ mutex_unlock(&host->clk_gate_mutex);
+}
+
+/**
+ * mmc_host_may_gate_card - check if this card may be gated
+ * @card: card to check.
+ */
+static bool mmc_host_may_gate_card(struct mmc_card *card)
+{
+ /* If there is no card we may gate it */
+ if (!card)
+ return true;
+ /*
+ * Don't gate SDIO cards! These need to be clocked at all times
+ * since they may be independent systems generating interrupts
+ * and other events. The clock requests counter from the core will
+ * go down to zero since the core does not need it, but we will not
+ * gate the clock, because there is somebody out there that may still
+ * be using it.
+ */
+ return !(card->quirks & MMC_QUIRK_BROKEN_CLK_GATING);
+}
+
+/**
+ * mmc_host_clk_release - gate off hardware MCI clocks
+ * @host: host to gate.
+ *
+ * Calls the host driver with ios.clock set to zero as often as possible
+ * in order to gate off hardware MCI clocks. Decrease clock reference
+ * count and schedule disabling of clock.
+ */
+void mmc_host_clk_release(struct mmc_host *host)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&host->clk_lock, flags);
+ host->clk_requests--;
+ if (mmc_host_may_gate_card(host->card) &&
+ !host->clk_requests)
+ schedule_delayed_work(&host->clk_gate_work,
+ msecs_to_jiffies(host->clkgate_delay));
+ spin_unlock_irqrestore(&host->clk_lock, flags);
+}
+
+/**
+ * mmc_host_clk_rate - get current clock frequency setting
+ * @host: host to get the clock frequency for.
+ *
+ * Returns current clock frequency regardless of gating.
+ */
+unsigned int mmc_host_clk_rate(struct mmc_host *host)
+{
+ unsigned long freq;
+ unsigned long flags;
+
+ spin_lock_irqsave(&host->clk_lock, flags);
+ if (host->clk_gated)
+ freq = host->clk_old;
+ else
+ freq = host->ios.clock;
+ spin_unlock_irqrestore(&host->clk_lock, flags);
+ return freq;
+}
+
+/**
+ * mmc_host_clk_init - set up clock gating code
+ * @host: host with potential clock to control
+ */
+static inline void mmc_host_clk_init(struct mmc_host *host)
+{
+ host->clk_requests = 0;
+ /* Hold MCI clock for 8 cycles by default */
+ host->clk_delay = 8;
+ /*
+ * Default clock gating delay is 0ms to avoid wasting power.
+ * This value can be tuned by writing into sysfs entry.
+ */
+ host->clkgate_delay = 0;
+ host->clk_gated = false;
+ INIT_DELAYED_WORK(&host->clk_gate_work, mmc_host_clk_gate_work);
+ spin_lock_init(&host->clk_lock);
+ mutex_init(&host->clk_gate_mutex);
+}
+
+/**
+ * mmc_host_clk_exit - shut down clock gating code
+ * @host: host with potential clock to control
+ */
+static inline void mmc_host_clk_exit(struct mmc_host *host)
+{
+ /*
+ * Wait for any outstanding gate and then make sure we're
+ * ungated before exiting.
+ */
+ if (cancel_delayed_work_sync(&host->clk_gate_work))
+ mmc_host_clk_gate_delayed(host);
+ if (host->clk_gated)
+ mmc_host_clk_hold(host);
+ /* There should be only one user now */
+ WARN_ON(host->clk_requests > 1);
+}
+
+static inline void mmc_host_clk_sysfs_init(struct mmc_host *host)
+{
+ host->clkgate_delay_attr.show = clkgate_delay_show;
+ host->clkgate_delay_attr.store = clkgate_delay_store;
+ sysfs_attr_init(&host->clkgate_delay_attr.attr);
+ host->clkgate_delay_attr.attr.name = "clkgate_delay";
+ host->clkgate_delay_attr.attr.mode = S_IRUGO | S_IWUSR;
+ if (device_create_file(&host->class_dev, &host->clkgate_delay_attr))
+ pr_err("%s: Failed to create clkgate_delay sysfs entry\n",
+ mmc_hostname(host));
+}
+#else
+
+static inline void mmc_host_clk_init(struct mmc_host *host)
+{
+}
+
+static inline void mmc_host_clk_exit(struct mmc_host *host)
+{
+}
+
+static inline void mmc_host_clk_sysfs_init(struct mmc_host *host)
+{
+}
+
+#endif
+
+/**
+ * mmc_of_parse() - parse host's device-tree node
+ * @host: host whose node should be parsed.
+ *
+ * To keep the rest of the MMC subsystem unaware of whether DT has been
+ * used to to instantiate and configure this host instance or not, we
+ * parse the properties and set respective generic mmc-host flags and
+ * parameters.
+ */
+int mmc_of_parse(struct mmc_host *host)
+{
+ struct device_node *np;
+ u32 bus_width;
+ int len, ret;
+ bool cd_cap_invert, cd_gpio_invert = false;
+ bool ro_cap_invert, ro_gpio_invert = false;
+
+ if (!host->parent || !host->parent->of_node)
+ return 0;
+
+ np = host->parent->of_node;
+
+ /* "bus-width" is translated to MMC_CAP_*_BIT_DATA flags */
+ if (of_property_read_u32(np, "bus-width", &bus_width) < 0) {
+ dev_dbg(host->parent,
+ "\"bus-width\" property is missing, assuming 1 bit.\n");
+ bus_width = 1;
+ }
+
+ switch (bus_width) {
+ case 8:
+ host->caps |= MMC_CAP_8_BIT_DATA;
+ /* Hosts capable of 8-bit transfers can also do 4 bits */
+ case 4:
+ host->caps |= MMC_CAP_4_BIT_DATA;
+ break;
+ case 1:
+ break;
+ default:
+ dev_err(host->parent,
+ "Invalid \"bus-width\" value %u!\n", bus_width);
+ return -EINVAL;
+ }
+
+ /* f_max is obtained from the optional "max-frequency" property */
+ of_property_read_u32(np, "max-frequency", &host->f_max);
+
+ /*
+ * Configure CD and WP pins. They are both by default active low to
+ * match the SDHCI spec. If GPIOs are provided for CD and / or WP, the
+ * mmc-gpio helpers are used to attach, configure and use them. If
+ * polarity inversion is specified in DT, one of MMC_CAP2_CD_ACTIVE_HIGH
+ * and MMC_CAP2_RO_ACTIVE_HIGH capability-2 flags is set. If the
+ * "broken-cd" property is provided, the MMC_CAP_NEEDS_POLL capability
+ * is set. If the "non-removable" property is found, the
+ * MMC_CAP_NONREMOVABLE capability is set and no card-detection
+ * configuration is performed.
+ */
+
+ /* Parse Card Detection */
+ if (of_find_property(np, "non-removable", &len)) {
+ host->caps |= MMC_CAP_NONREMOVABLE;
+ } else {
+ cd_cap_invert = of_property_read_bool(np, "cd-inverted");
+
+ if (of_find_property(np, "broken-cd", &len))
+ host->caps |= MMC_CAP_NEEDS_POLL;
+
+ ret = mmc_gpiod_request_cd(host, "cd", 0, true,
+ 0, &cd_gpio_invert);
+ if (!ret)
+ dev_info(host->parent, "Got CD GPIO\n");
+ else if (ret != -ENOENT)
+ return ret;
+
+ /*
+ * There are two ways to flag that the CD line is inverted:
+ * through the cd-inverted flag and by the GPIO line itself
+ * being inverted from the GPIO subsystem. This is a leftover
+ * from the times when the GPIO subsystem did not make it
+ * possible to flag a line as inverted.
+ *
+ * If the capability on the host AND the GPIO line are
+ * both inverted, the end result is that the CD line is
+ * not inverted.
+ */
+ if (cd_cap_invert ^ cd_gpio_invert)
+ host->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH;
+ }
+
+ /* Parse Write Protection */
+ ro_cap_invert = of_property_read_bool(np, "wp-inverted");
+
+ ret = mmc_gpiod_request_ro(host, "wp", 0, false, 0, &ro_gpio_invert);
+ if (!ret)
+ dev_info(host->parent, "Got WP GPIO\n");
+ else if (ret != -ENOENT)
+ return ret;
+
+ /* See the comment on CD inversion above */
+ if (ro_cap_invert ^ ro_gpio_invert)
+ host->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;
+
+ if (of_find_property(np, "cap-sd-highspeed", &len))
+ host->caps |= MMC_CAP_SD_HIGHSPEED;
+ if (of_find_property(np, "cap-mmc-highspeed", &len))
+ host->caps |= MMC_CAP_MMC_HIGHSPEED;
+ if (of_find_property(np, "sd-uhs-sdr12", &len))
+ host->caps |= MMC_CAP_UHS_SDR12;
+ if (of_find_property(np, "sd-uhs-sdr25", &len))
+ host->caps |= MMC_CAP_UHS_SDR25;
+ if (of_find_property(np, "sd-uhs-sdr50", &len))
+ host->caps |= MMC_CAP_UHS_SDR50;
+ if (of_find_property(np, "sd-uhs-sdr104", &len))
+ host->caps |= MMC_CAP_UHS_SDR104;
+ if (of_find_property(np, "sd-uhs-ddr50", &len))
+ host->caps |= MMC_CAP_UHS_DDR50;
+ if (of_find_property(np, "cap-power-off-card", &len))
+ host->caps |= MMC_CAP_POWER_OFF_CARD;
+ if (of_find_property(np, "cap-sdio-irq", &len))
+ host->caps |= MMC_CAP_SDIO_IRQ;
+ if (of_find_property(np, "full-pwr-cycle", &len))
+ host->caps2 |= MMC_CAP2_FULL_PWR_CYCLE;
+ if (of_find_property(np, "keep-power-in-suspend", &len))
+ host->pm_caps |= MMC_PM_KEEP_POWER;
+ if (of_find_property(np, "enable-sdio-wakeup", &len))
+ host->pm_caps |= MMC_PM_WAKE_SDIO_IRQ;
+ if (of_find_property(np, "mmc-ddr-1_8v", &len))
+ host->caps |= MMC_CAP_1_8V_DDR;
+ if (of_find_property(np, "mmc-ddr-1_2v", &len))
+ host->caps |= MMC_CAP_1_2V_DDR;
+ if (of_find_property(np, "mmc-hs200-1_8v", &len))
+ host->caps2 |= MMC_CAP2_HS200_1_8V_SDR;
+ if (of_find_property(np, "mmc-hs200-1_2v", &len))
+ host->caps2 |= MMC_CAP2_HS200_1_2V_SDR;
+ if (of_find_property(np, "mmc-hs400-1_8v", &len))
+ host->caps2 |= MMC_CAP2_HS400_1_8V | MMC_CAP2_HS200_1_8V_SDR;
+ if (of_find_property(np, "mmc-hs400-1_2v", &len))
+ host->caps2 |= MMC_CAP2_HS400_1_2V | MMC_CAP2_HS200_1_2V_SDR;
+
+ host->dsr_req = !of_property_read_u32(np, "dsr", &host->dsr);
+ if (host->dsr_req && (host->dsr & ~0xffff)) {
+ dev_err(host->parent,
+ "device tree specified broken value for DSR: 0x%x, ignoring\n",
+ host->dsr);
+ host->dsr_req = 0;
+ }
+
+ return mmc_pwrseq_alloc(host);
+}
+
+EXPORT_SYMBOL(mmc_of_parse);
+
+/**
+ * mmc_alloc_host - initialise the per-host structure.
+ * @extra: sizeof private data structure
+ * @dev: pointer to host device model structure
+ *
+ * Initialise the per-host structure.
+ */
+struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
+{
+ int err;
+ struct mmc_host *host;
+
+ host = kzalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL);
+ if (!host)
+ return NULL;
+
+ /* scanning will be enabled when we're ready */
+ host->rescan_disable = 1;
+ idr_preload(GFP_KERNEL);
+ spin_lock(&mmc_host_lock);
+ err = idr_alloc(&mmc_host_idr, host, 0, 0, GFP_NOWAIT);
+ if (err >= 0)
+ host->index = err;
+ spin_unlock(&mmc_host_lock);
+ idr_preload_end();
+ if (err < 0) {
+ kfree(host);
+ return NULL;
+ }
+
+ dev_set_name(&host->class_dev, "mmc%d", host->index);
+
+ host->parent = dev;
+ host->class_dev.parent = dev;
+ host->class_dev.class = &mmc_host_class;
+ device_initialize(&host->class_dev);
+
+ if (mmc_gpio_alloc(host)) {
+ put_device(&host->class_dev);
+ return NULL;
+ }
+
+ mmc_host_clk_init(host);
+
+ spin_lock_init(&host->lock);
+ init_waitqueue_head(&host->wq);
+ INIT_DELAYED_WORK(&host->detect, mmc_rescan);
+#ifdef CONFIG_PM
+ host->pm_notify.notifier_call = mmc_pm_notify;
+#endif
+
+ /*
+ * By default, hosts do not support SGIO or large requests.
+ * They have to set these according to their abilities.
+ */
+ host->max_segs = 1;
+ host->max_seg_size = PAGE_CACHE_SIZE;
+
+ host->max_req_size = PAGE_CACHE_SIZE;
+ host->max_blk_size = 512;
+ host->max_blk_count = PAGE_CACHE_SIZE / 512;
+
+ return host;
+}
+
+EXPORT_SYMBOL(mmc_alloc_host);
+
+/**
+ * mmc_add_host - initialise host hardware
+ * @host: mmc host
+ *
+ * Register the host with the driver model. The host must be
+ * prepared to start servicing requests before this function
+ * completes.
+ */
+int mmc_add_host(struct mmc_host *host)
+{
+ int err;
+
+ WARN_ON((host->caps & MMC_CAP_SDIO_IRQ) &&
+ !host->ops->enable_sdio_irq);
+
+ err = device_add(&host->class_dev);
+ if (err)
+ return err;
+
+ led_trigger_register_simple(dev_name(&host->class_dev), &host->led);
+
+#ifdef CONFIG_DEBUG_FS
+ mmc_add_host_debugfs(host);
+#endif
+ mmc_host_clk_sysfs_init(host);
+
+ mmc_start_host(host);
+ register_pm_notifier(&host->pm_notify);
+
+ return 0;
+}
+
+EXPORT_SYMBOL(mmc_add_host);
+
+/**
+ * mmc_remove_host - remove host hardware
+ * @host: mmc host
+ *
+ * Unregister and remove all cards associated with this host,
+ * and power down the MMC bus. No new requests will be issued
+ * after this function has returned.
+ */
+void mmc_remove_host(struct mmc_host *host)
+{
+ unregister_pm_notifier(&host->pm_notify);
+ mmc_stop_host(host);
+
+#ifdef CONFIG_DEBUG_FS
+ mmc_remove_host_debugfs(host);
+#endif
+
+ device_del(&host->class_dev);
+
+ led_trigger_unregister_simple(host->led);
+
+ mmc_host_clk_exit(host);
+}
+
+EXPORT_SYMBOL(mmc_remove_host);
+
+/**
+ * mmc_free_host - free the host structure
+ * @host: mmc host
+ *
+ * Free the host once all references to it have been dropped.
+ */
+void mmc_free_host(struct mmc_host *host)
+{
+ mmc_pwrseq_free(host);
+ put_device(&host->class_dev);
+}
+
+EXPORT_SYMBOL(mmc_free_host);
Code Review / kvmfornfv.git / blobdiff