diff --git a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
index 502b3b8..bd8470a 100644
--- a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
+++ b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
@@ -26,6 +26,15 @@ Required properties:
 	"cal"	- reference clock for RCLK delay calibration (optional)
 	"sleep"	- sleep clock for RCLK delay calibration (optional)
 
+Optional Properties:
+- qcom,devfreq,freq-table - specifies supported frequencies for clock scaling.
+				    Clock scaling logic shall toggle between these frequencies based
+				    on card load. In case the defined frequencies are over or below
+				    the supported card frequencies, they will be overridden
+				    during card init. In case this entry is not supplied,
+				    the driver will construct one based on the card
+				    supported max and min frequencies.
+				    The frequencies must be ordered from lowest to highest.
 Example:
 
 	sdhc_1: sdhci@f9824900 {
@@ -43,6 +52,7 @@ Example:
 
 		clocks = <&gcc GCC_SDCC1_APPS_CLK>, <&gcc GCC_SDCC1_AHB_CLK>;
 		clock-names = "core", "iface";
+		qcom,devfreq,freq-table = <52000000 200000000>;
 	};
 
 	sdhc_2: sdhci@f98a4900 {
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 281826d..0eaee42 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -14,6 +14,7 @@
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/completion.h>
+#include <linux/devfreq.h>
 #include <linux/device.h>
 #include <linux/delay.h>
 #include <linux/pagemap.h>
@@ -112,6 +113,556 @@ static inline void mmc_should_fail_request(struct mmc_host *host,
 
 #endif /* CONFIG_FAIL_MMC_REQUEST */
 
+static bool mmc_is_data_request(struct mmc_request *mmc_request)
+{
+	switch (mmc_request->cmd->opcode) {
+	case MMC_READ_SINGLE_BLOCK:
+	case MMC_READ_MULTIPLE_BLOCK:
+	case MMC_WRITE_BLOCK:
+	case MMC_WRITE_MULTIPLE_BLOCK:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static void mmc_clk_scaling_start_busy(struct mmc_host *host, bool lock_needed)
+{
+	struct mmc_devfeq_clk_scaling *clk_scaling = &host->clk_scaling;
+
+	if (!clk_scaling->enable)
+		return;
+
+	if (lock_needed)
+		spin_lock_bh(&clk_scaling->lock);
+
+	clk_scaling->start_busy = ktime_get();
+	clk_scaling->is_busy_started = true;
+
+	if (lock_needed)
+		spin_unlock_bh(&clk_scaling->lock);
+}
+
+static void mmc_clk_scaling_stop_busy(struct mmc_host *host, bool lock_needed)
+{
+	struct mmc_devfeq_clk_scaling *clk_scaling = &host->clk_scaling;
+
+	if (!clk_scaling->enable)
+		return;
+
+	if (lock_needed)
+		spin_lock_bh(&clk_scaling->lock);
+
+	if (!clk_scaling->is_busy_started) {
+		WARN_ON(1);
+		goto out;
+	}
+
+	clk_scaling->total_busy_time_us +=
+		ktime_to_us(ktime_sub(ktime_get(),
+			clk_scaling->start_busy));
+	pr_debug("%s: accumulated busy time is %lu usec\n",
+		mmc_hostname(host), clk_scaling->total_busy_time_us);
+	clk_scaling->is_busy_started = false;
+
+out:
+	if (lock_needed)
+		spin_unlock_bh(&clk_scaling->lock);
+}
+
+/**
+ * mmc_can_scale_clk() - Check clock scaling capability
+ * @host: pointer to mmc host structure
+ */
+bool mmc_can_scale_clk(struct mmc_host *host)
+{
+	if (!host) {
+		pr_err("bad host parameter\n");
+		WARN_ON(1);
+		return false;
+	}
+
+	return host->caps2 & MMC_CAP2_CLK_SCALE;
+}
+EXPORT_SYMBOL(mmc_can_scale_clk);
+
+static int mmc_devfreq_get_dev_status(struct device *dev,
+		struct devfreq_dev_status *status)
+{
+	struct mmc_host *host = container_of(dev, struct mmc_host, class_dev);
+	struct mmc_devfeq_clk_scaling *clk_scaling;
+
+	if (!host) {
+		pr_err("bad host parameter\n");
+		WARN_ON(1);
+		return -EINVAL;
+	}
+
+	clk_scaling = &host->clk_scaling;
+
+	if (!clk_scaling->enable)
+		return 0;
+
+	spin_lock_bh(&clk_scaling->lock);
+
+	/* accumulate the busy time of ongoing work */
+	memset(status, 0, sizeof(*status));
+	if (clk_scaling->is_busy_started) {
+			mmc_clk_scaling_stop_busy(host, false);
+			mmc_clk_scaling_start_busy(host, false);
+	}
+
+	status->busy_time = clk_scaling->total_busy_time_us;
+	status->total_time = ktime_to_us(ktime_sub(ktime_get(),
+		clk_scaling->measure_interval_start));
+	clk_scaling->total_busy_time_us = 0;
+	status->current_frequency = clk_scaling->curr_freq;
+	clk_scaling->measure_interval_start = ktime_get();
+
+	pr_debug("%s: status: load = %lu%% - total_time=%lu busy_time = %lu, clk=%lu\n",
+		mmc_hostname(host),
+		(status->busy_time*100)/status->total_time,
+		status->total_time, status->busy_time,
+		status->current_frequency);
+
+	spin_unlock_bh(&clk_scaling->lock);
+
+	return 0;
+}
+
+static bool mmc_is_valid_state_for_clk_scaling(struct mmc_host *host)
+{
+	struct mmc_card *card = host->card;
+	u32 status;
+
+	/*
+	 * If the current partition type is RPMB, clock switching may not
+	 * work properly as sending tuning command (CMD21) is illegal in
+	 * this mode.
+	 */
+	if (!card || (mmc_card_mmc(card) &&
+			(card->part_curr == EXT_CSD_PART_CONFIG_ACC_RPMB ||
+			mmc_card_doing_bkops(card))))
+		return false;
+
+	if (mmc_send_status(card, &status)) {
+		pr_err("%s: Get card status fail\n", mmc_hostname(card->host));
+		return false;
+	}
+
+	return R1_CURRENT_STATE(status) == R1_STATE_TRAN;
+}
+
+int mmc_clk_update_freq(struct mmc_host *host,
+		unsigned long freq, enum mmc_load state)
+{
+	int err = 0;
+
+	if (!host) {
+		pr_err("bad host parameter\n");
+		WARN_ON(1);
+		return -EINVAL;
+	}
+
+	/* make sure the card supports the frequency we want */
+	if (unlikely(freq > host->card->clk_scaling_highest)) {
+		freq = host->card->clk_scaling_highest;
+		pr_warn("%s: %s: frequency was overridden to %lu\n",
+				mmc_hostname(host), __func__,
+				host->card->clk_scaling_highest);
+	}
+
+	if (unlikely(freq < host->card->clk_scaling_lowest)) {
+		freq = host->card->clk_scaling_lowest;
+		pr_warn("%s: %s: frequency was overridden to %lu\n",
+			mmc_hostname(host), __func__,
+			host->card->clk_scaling_lowest);
+	}
+
+	if (freq == host->clk_scaling.curr_freq)
+		goto out;
+
+	if (host->ops->notify_load) {
+		err = host->ops->notify_load(host, state);
+		if (err) {
+			pr_err("%s: %s: fail on notify_load\n",
+				mmc_hostname(host), __func__);
+			goto out;
+		}
+	}
+
+	if (!mmc_is_valid_state_for_clk_scaling(host)) {
+		pr_debug("%s: invalid state for clock scaling - skipping",
+			mmc_hostname(host));
+		goto invalid_state;
+	}
+
+	err = host->bus_ops->change_bus_speed(host, &freq);
+	if (!err)
+		host->clk_scaling.curr_freq = freq;
+	else
+		pr_err("%s: %s: failed (%d) at freq=%lu\n",
+			mmc_hostname(host), __func__, err, freq);
+
+invalid_state:
+	if (err) {
+		/* restore previous state */
+		if (host->ops->notify_load)
+			if (host->ops->notify_load(host,
+				host->clk_scaling.state))
+				pr_err("%s: %s: fail on notify_load restore\n",
+					mmc_hostname(host), __func__);
+	}
+out:
+	return err;
+}
+EXPORT_SYMBOL(mmc_clk_update_freq);
+
+static int mmc_devfreq_set_target(struct device *dev,
+				unsigned long *freq, u32 devfreq_flags)
+{
+	struct mmc_host *host = container_of(dev, struct mmc_host, class_dev);
+	struct mmc_devfeq_clk_scaling *clk_scaling;
+	int err = 0;
+	int abort;
+	unsigned long pflags = current->flags;
+
+	/* Ensure scaling would happen even in memory pressure conditions */
+	current->flags |= PF_MEMALLOC;
+
+	if (!(host && freq)) {
+		pr_err("%s: unexpected host/freq parameter\n", __func__);
+		err = -EINVAL;
+		goto out;
+	}
+
+	clk_scaling = &host->clk_scaling;
+
+	if (!clk_scaling->enable)
+		goto out;
+
+	pr_debug("%s: target freq = %lu (%s)\n", mmc_hostname(host),
+		*freq, current->comm);
+
+	if ((clk_scaling->curr_freq == *freq) ||
+		clk_scaling->skip_clk_scale_freq_update)
+		goto out;
+
+	/* No need to scale the clocks if they are gated */
+	if (!host->ios.clock)
+		goto out;
+
+	spin_lock_bh(&clk_scaling->lock);
+	if (clk_scaling->clk_scaling_in_progress) {
+		pr_debug("%s: clocks scaling is already in-progress by mmc thread\n",
+			mmc_hostname(host));
+		spin_unlock_bh(&clk_scaling->lock);
+		goto out;
+	}
+	clk_scaling->need_freq_change = true;
+	clk_scaling->target_freq = *freq;
+	clk_scaling->state = *freq < clk_scaling->curr_freq ?
+		MMC_LOAD_LOW : MMC_LOAD_HIGH;
+	spin_unlock_bh(&clk_scaling->lock);
+
+	abort = __mmc_claim_host(host, NULL, &clk_scaling->devfreq_abort);
+	if (abort)
+		goto out;
+
+	/*
+	 * In case we were able to claim host there is no need to
+	 * defer the frequency change. It will be done now
+	 */
+	clk_scaling->need_freq_change = false;
+
+	err = mmc_clk_update_freq(host, *freq, clk_scaling->state);
+	if (err && err != -EAGAIN) {
+		pr_err("%s: clock scale to %lu failed with error %d\n",
+			mmc_hostname(host), *freq, err);
+	} else {
+		pr_debug("%s: clock change to %lu finished successfully (%s)\n",
+			mmc_hostname(host), *freq, current->comm);
+	}
+
+	mmc_release_host(host);
+out:
+	current->flags &= ~PF_MEMALLOC;
+	current->flags |= pflags & PF_MEMALLOC;
+	return err;
+}
+
+/**
+ * mmc_deferred_scaling() - scale clocks from data path (mmc thread context)
+ * @host: pointer to mmc host structure
+ *
+ * This function does clock scaling in case "need_freq_change" flag was set
+ * by the clock scaling logic.
+ */
+void mmc_deferred_scaling(struct mmc_host *host)
+{
+	unsigned long target_freq;
+	int err;
+
+	if (!host->clk_scaling.enable)
+		return;
+
+	spin_lock_bh(&host->clk_scaling.lock);
+
+	if (host->clk_scaling.clk_scaling_in_progress ||
+		!(host->clk_scaling.need_freq_change)) {
+		spin_unlock_bh(&host->clk_scaling.lock);
+		return;
+	}
+
+
+	atomic_inc(&host->clk_scaling.devfreq_abort);
+	target_freq = host->clk_scaling.target_freq;
+	host->clk_scaling.clk_scaling_in_progress = true;
+	host->clk_scaling.need_freq_change = false;
+	spin_unlock_bh(&host->clk_scaling.lock);
+	pr_debug("%s: doing deferred frequency change (%lu) (%s)\n",
+				mmc_hostname(host),
+				target_freq, current->comm);
+
+	err = mmc_clk_update_freq(host, target_freq,
+		host->clk_scaling.state);
+	if (err && err != -EAGAIN) {
+		pr_err("%s: failed on deferred scale clocks (%d)\n",
+			mmc_hostname(host), err);
+	} else {
+		pr_debug("%s: clocks were successfully scaled to %lu (%s)\n",
+			mmc_hostname(host),
+			target_freq, current->comm);
+	}
+	host->clk_scaling.clk_scaling_in_progress = false;
+	atomic_dec(&host->clk_scaling.devfreq_abort);
+}
+EXPORT_SYMBOL(mmc_deferred_scaling);
+
+static int mmc_devfreq_create_freq_table(struct mmc_host *host)
+{
+	int i;
+	struct mmc_devfeq_clk_scaling *clk_scaling = &host->clk_scaling;
+
+	pr_debug("%s: supported: lowest=%lu, highest=%lu\n",
+		mmc_hostname(host),
+		host->card->clk_scaling_lowest,
+		host->card->clk_scaling_highest);
+
+	/*
+	 * Create the frequency table and initialize it with default values.
+	 * Initialize it with platform specific frequencies if the frequency
+	 * table supplied by platform driver is present, otherwise initialize
+	 * it with min and max frequencies supported by the card.
+	 */
+	if (!clk_scaling->freq_table) {
+		if (clk_scaling->pltfm_freq_table_sz)
+			clk_scaling->freq_table_sz =
+				clk_scaling->pltfm_freq_table_sz;
+		else
+			clk_scaling->freq_table_sz = 2;
+
+		clk_scaling->freq_table = kzalloc(
+			(clk_scaling->freq_table_sz *
+			sizeof(*(clk_scaling->freq_table))), GFP_KERNEL);
+		if (!clk_scaling->freq_table)
+			return -ENOMEM;
+
+		if (clk_scaling->pltfm_freq_table) {
+			memcpy(clk_scaling->freq_table,
+				clk_scaling->pltfm_freq_table,
+				(clk_scaling->pltfm_freq_table_sz *
+				sizeof(*(clk_scaling->pltfm_freq_table))));
+		} else {
+			pr_debug("%s: no frequency table defined -  setting default\n",
+				mmc_hostname(host));
+			clk_scaling->freq_table[0] =
+				host->card->clk_scaling_lowest;
+			clk_scaling->freq_table[1] =
+				host->card->clk_scaling_highest;
+			goto out;
+		}
+	}
+
+	if (host->card->clk_scaling_lowest >
+		clk_scaling->freq_table[0])
+		pr_debug("%s: frequency table undershot possible freq\n",
+			mmc_hostname(host));
+
+	for (i = 0; i < clk_scaling->freq_table_sz; i++) {
+		if (clk_scaling->freq_table[i] <=
+			host->card->clk_scaling_highest)
+			continue;
+		clk_scaling->freq_table[i] =
+			host->card->clk_scaling_highest;
+		clk_scaling->freq_table_sz = i + 1;
+		pr_debug("%s: frequency table overshot possible freq (%d)\n",
+				mmc_hostname(host), clk_scaling->freq_table[i]);
+		break;
+	}
+
+out:
+	/**
+	 * devfreq requires unsigned long type freq_table while the
+	 * freq_table in clk_scaling is un32. Here allocates an individual
+	 * memory space for it and release it when exit clock scaling.
+	 */
+	clk_scaling->devfreq_profile.freq_table =  kzalloc(
+			clk_scaling->freq_table_sz *
+			sizeof(*(clk_scaling->devfreq_profile.freq_table)),
+			GFP_KERNEL);
+	if (!clk_scaling->devfreq_profile.freq_table)
+		return -ENOMEM;
+	clk_scaling->devfreq_profile.max_state = clk_scaling->freq_table_sz;
+
+	for (i = 0; i < clk_scaling->freq_table_sz; i++) {
+		clk_scaling->devfreq_profile.freq_table[i] =
+			clk_scaling->freq_table[i];
+		pr_debug("%s: freq[%d] = %u\n",
+			mmc_hostname(host), i, clk_scaling->freq_table[i]);
+	}
+
+	return 0;
+}
+
+/**
+ * mmc_init_devfreq_clk_scaling() - Initialize clock scaling
+ * @host: pointer to mmc host structure
+ *
+ * Initialize clock scaling for supported hosts. It is assumed that the caller
+ * ensure clock is running at maximum possible frequency before calling this
+ * function. Shall use struct devfreq_simple_ondemand_data to configure
+ * governor.
+ */
+int mmc_init_clk_scaling(struct mmc_host *host)
+{
+	int err;
+
+	if (!host || !host->card) {
+		pr_err("%s: unexpected host/card parameters\n",
+			__func__);
+		return -EINVAL;
+	}
+
+	if (!mmc_can_scale_clk(host) ||
+		!host->bus_ops->change_bus_speed) {
+		pr_debug("%s: clock scaling is not supported\n",
+			mmc_hostname(host));
+		return 0;
+	}
+
+	pr_debug("registering %s dev (%p) to devfreq",
+		mmc_hostname(host),
+		mmc_classdev(host));
+
+	if (host->clk_scaling.devfreq) {
+		pr_err("%s: dev is already registered for dev %p\n",
+			mmc_hostname(host),
+			mmc_dev(host));
+		return -EPERM;
+	}
+	spin_lock_init(&host->clk_scaling.lock);
+	atomic_set(&host->clk_scaling.devfreq_abort, 0);
+	host->clk_scaling.curr_freq = host->ios.clock;
+	host->clk_scaling.clk_scaling_in_progress = false;
+	host->clk_scaling.need_freq_change = false;
+	host->clk_scaling.is_busy_started = false;
+
+	host->clk_scaling.devfreq_profile.polling_ms =
+		host->clk_scaling.polling_delay_ms;
+	host->clk_scaling.devfreq_profile.get_dev_status =
+		mmc_devfreq_get_dev_status;
+	host->clk_scaling.devfreq_profile.target = mmc_devfreq_set_target;
+	host->clk_scaling.devfreq_profile.initial_freq = host->ios.clock;
+
+	host->clk_scaling.ondemand_gov_data.simple_scaling = true;
+	host->clk_scaling.ondemand_gov_data.upthreshold =
+		host->clk_scaling.upthreshold;
+	host->clk_scaling.ondemand_gov_data.downdifferential =
+		host->clk_scaling.upthreshold - host->clk_scaling.downthreshold;
+
+	err = mmc_devfreq_create_freq_table(host);
+	if (err) {
+		pr_err("%s: fail to create devfreq frequency table\n",
+			mmc_hostname(host));
+		return err;
+	}
+
+	pr_debug("%s: adding devfreq with: upthreshold=%u downthreshold=%u polling=%u\n",
+		mmc_hostname(host),
+		host->clk_scaling.ondemand_gov_data.upthreshold,
+		host->clk_scaling.ondemand_gov_data.downdifferential,
+		host->clk_scaling.devfreq_profile.polling_ms);
+	host->clk_scaling.devfreq = devfreq_add_device(
+		mmc_classdev(host),
+		&host->clk_scaling.devfreq_profile,
+		"simple_ondemand",
+		&host->clk_scaling.ondemand_gov_data);
+	if (!host->clk_scaling.devfreq) {
+		pr_err("%s: unable to register with devfreq\n",
+			mmc_hostname(host));
+		return -EPERM;
+	}
+
+	pr_debug("%s: clk scaling is enabled for device %s (%p) with devfreq %p (clock = %uHz)\n",
+		mmc_hostname(host),
+		dev_name(mmc_classdev(host)),
+		mmc_classdev(host),
+		host->clk_scaling.devfreq,
+		host->ios.clock);
+
+	host->clk_scaling.enable = true;
+
+	return err;
+}
+EXPORT_SYMBOL(mmc_init_clk_scaling);
+
+/**
+ * mmc_exit_devfreq_clk_scaling() - Disable clock scaling
+ * @host: pointer to mmc host structure
+ *
+ * Disable clock scaling permanently.
+ */
+int mmc_exit_clk_scaling(struct mmc_host *host)
+{
+	int err;
+
+	if (!host) {
+		pr_err("%s: bad host parameter\n", __func__);
+		WARN_ON(1);
+		return -EINVAL;
+	}
+
+	if (!mmc_can_scale_clk(host))
+		return 0;
+
+	if (!host->clk_scaling.devfreq) {
+		pr_err("%s: %s: no devfreq is assosiated with this device\n",
+			mmc_hostname(host), __func__);
+		return -EPERM;
+	}
+
+	err = devfreq_remove_device(host->clk_scaling.devfreq);
+	if (err) {
+		pr_err("%s: remove devfreq failed (%d)\n",
+			mmc_hostname(host), err);
+		return err;
+	}
+
+	kfree(host->clk_scaling.devfreq_profile.freq_table);
+
+	host->clk_scaling.devfreq = NULL;
+	atomic_set(&host->clk_scaling.devfreq_abort, 1);
+
+	kfree(host->clk_scaling.freq_table);
+	host->clk_scaling.freq_table = NULL;
+
+	pr_debug("%s: devfreq was removed\n", mmc_hostname(host));
+
+	return 0;
+}
+EXPORT_SYMBOL(mmc_exit_clk_scaling);
+
 static inline void mmc_complete_cmd(struct mmc_request *mrq)
 {
 	if (mrq->cap_cmd_during_tfr && !completion_done(&mrq->cmd_completion))
@@ -143,6 +694,9 @@ void mmc_request_done(struct mmc_host *host, struct mmc_request *mrq)
 	struct mmc_command *cmd = mrq->cmd;
 	int err = cmd->error;
 
+	if (host->clk_scaling.is_busy_started)
+		mmc_clk_scaling_stop_busy(host, true);
+
 	/* Flag re-tuning needed on CRC errors */
 	if ((cmd->opcode != MMC_SEND_TUNING_BLOCK &&
 	    cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200) &&
@@ -354,6 +908,12 @@ int mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)
 		return err;
 
 	led_trigger_event(host->led, LED_FULL);
+
+	if (mmc_is_data_request(mrq)) {
+		mmc_deferred_scaling(host);
+		mmc_clk_scaling_start_busy(host, true);
+	}
+
 	__mmc_start_request(host, mrq);
 
 	return 0;
diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h
index 9d8f09a..fc0a9b7 100644
--- a/drivers/mmc/core/core.h
+++ b/drivers/mmc/core/core.h
@@ -34,6 +34,7 @@ struct mmc_bus_ops {
 	int (*shutdown)(struct mmc_host *);
 	int (*hw_reset)(struct mmc_host *);
 	int (*sw_reset)(struct mmc_host *);
+	int (*change_bus_speed)(struct mmc_host *, unsigned long *);
 };
 
 void mmc_attach_bus(struct mmc_host *host, const struct mmc_bus_ops *ops);
@@ -46,6 +47,8 @@ struct device_node *mmc_of_find_child_device(struct mmc_host *host,
 
 void mmc_set_chip_select(struct mmc_host *host, int mode);
 void mmc_set_clock(struct mmc_host *host, unsigned int hz);
+int mmc_clk_update_freq(struct mmc_host *host,
+		unsigned long freq, enum mmc_load state);
 void mmc_set_bus_mode(struct mmc_host *host, unsigned int mode);
 void mmc_set_bus_width(struct mmc_host *host, unsigned int width);
 u32 mmc_select_voltage(struct mmc_host *host, u32 ocr);
@@ -91,6 +94,10 @@ static inline void mmc_delay(unsigned int ms)
 void mmc_add_card_debugfs(struct mmc_card *card);
 void mmc_remove_card_debugfs(struct mmc_card *card);
 
+extern bool mmc_can_scale_clk(struct mmc_host *host);
+extern int mmc_init_clk_scaling(struct mmc_host *host);
+extern int mmc_exit_clk_scaling(struct mmc_host *host);
+
 int mmc_execute_tuning(struct mmc_card *card);
 int mmc_hs200_to_hs400(struct mmc_card *card);
 int mmc_hs400_to_hs200(struct mmc_card *card);
diff --git a/drivers/mmc/core/debugfs.c b/drivers/mmc/core/debugfs.c
index d2275c5..630ca8e 100644
--- a/drivers/mmc/core/debugfs.c
+++ b/drivers/mmc/core/debugfs.c
@@ -225,6 +225,43 @@ static int mmc_clock_opt_set(void *data, u64 val)
 DEFINE_SIMPLE_ATTRIBUTE(mmc_clock_fops, mmc_clock_opt_get, mmc_clock_opt_set,
 	"%llu\n");
 
+#include <linux/delay.h>
+
+static int mmc_scale_get(void *data, u64 *val)
+{
+	struct mmc_host *host = data;
+
+	*val = host->clk_scaling.curr_freq;
+
+	return 0;
+}
+
+static int mmc_scale_set(void *data, u64 val)
+{
+	int err = 0;
+	struct mmc_host *host = data;
+
+	mmc_claim_host(host);
+
+	/* change frequency from sysfs manually */
+	err = mmc_clk_update_freq(host, val, host->clk_scaling.state);
+	if (err == -EAGAIN)
+		err = 0;
+	else if (err)
+		pr_err("%s: clock scale to %llu failed with error %d\n",
+			mmc_hostname(host), val, err);
+	else
+		pr_debug("%s: clock change to %llu finished successfully (%s)\n",
+			mmc_hostname(host), val, current->comm);
+
+	mmc_release_host(host);
+
+	return err;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(mmc_scale_fops, mmc_scale_get, mmc_scale_set,
+	"%llu\n");
+
 void mmc_add_host_debugfs(struct mmc_host *host)
 {
 	struct dentry *root;
@@ -253,6 +290,15 @@ void mmc_add_host_debugfs(struct mmc_host *host)
 			&mmc_clock_fops))
 		goto err_node;
 
+	if (!debugfs_create_file("scale", 0600, root, host,
+		&mmc_scale_fops))
+		goto err_node;
+
+	if (!debugfs_create_bool("skip_clk_scale_freq_update",
+		0600, root,
+		&host->clk_scaling.skip_clk_scale_freq_update))
+		goto err_node;
+
 #ifdef CONFIG_FAIL_MMC_REQUEST
 	if (fail_request)
 		setup_fault_attr(&fail_default_attr, fail_request);
diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
index abf9e88..1e46aa4 100644
--- a/drivers/mmc/core/host.c
+++ b/drivers/mmc/core/host.c
@@ -32,6 +32,10 @@
 #include "pwrseq.h"
 #include "sdio_ops.h"
 
+#define MMC_DEVFRQ_DEFAULT_UP_THRESHOLD 35
+#define MMC_DEVFRQ_DEFAULT_DOWN_THRESHOLD 5
+#define MMC_DEVFRQ_DEFAULT_POLLING_MSEC 100
+
 #define cls_dev_to_mmc_host(d)	container_of(d, struct mmc_host, class_dev)
 
 static DEFINE_IDA(mmc_host_ida);
@@ -435,6 +439,10 @@ int mmc_add_host(struct mmc_host *host)
 		return err;
 
 	led_trigger_register_simple(dev_name(&host->class_dev), &host->led);
+	host->clk_scaling.upthreshold = MMC_DEVFRQ_DEFAULT_UP_THRESHOLD;
+	host->clk_scaling.downthreshold = MMC_DEVFRQ_DEFAULT_DOWN_THRESHOLD;
+	host->clk_scaling.polling_delay_ms = MMC_DEVFRQ_DEFAULT_POLLING_MSEC;
+	host->clk_scaling.skip_clk_scale_freq_update = false;
 
 #ifdef CONFIG_DEBUG_FS
 	mmc_add_host_debugfs(host);
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 4466f5d..c8aedf3 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1526,6 +1526,170 @@ static int mmc_hs200_tuning(struct mmc_card *card)
 }
 
 /*
+ * Scale down from HS400 to HS in order to allow frequency change.
+ * This is needed for cards that doesn't support changing frequency in HS400
+ */
+static int mmc_scale_low(struct mmc_host *host, unsigned long freq)
+{
+	int err = 0;
+
+	mmc_set_timing(host, MMC_TIMING_LEGACY);
+	mmc_set_clock(host, MMC_HIGH_26_MAX_DTR);
+
+	err = mmc_select_hs(host->card);
+	if (err) {
+		pr_err("%s: %s: scaling low: failed (%d)\n",
+		       mmc_hostname(host), __func__, err);
+		return err;
+	}
+
+	err = mmc_select_bus_width(host->card);
+	if (err < 0) {
+		pr_err("%s: %s: select_bus_width failed(%d)\n",
+			mmc_hostname(host), __func__, err);
+		return err;
+	}
+
+	mmc_set_clock(host, freq);
+
+	return 0;
+}
+
+/*
+ * Scale UP from HS to HS200/H400
+ */
+static int mmc_scale_high(struct mmc_host *host)
+{
+	int err = 0;
+
+	if (mmc_card_ddr52(host->card)) {
+		mmc_set_timing(host, MMC_TIMING_LEGACY);
+		mmc_set_clock(host, MMC_HIGH_26_MAX_DTR);
+	}
+
+	if (!host->card->ext_csd.strobe_support) {
+		if (!(host->card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200)) {
+			pr_err("%s: %s: card does not support HS200\n",
+				mmc_hostname(host), __func__);
+			WARN_ON(1);
+			return -EPERM;
+		}
+
+		err = mmc_select_hs200(host->card);
+		if (err) {
+			pr_err("%s: %s: selecting HS200 failed (%d)\n",
+				mmc_hostname(host), __func__, err);
+			return err;
+		}
+
+		mmc_set_bus_speed(host->card);
+
+		err = mmc_hs200_tuning(host->card);
+		if (err) {
+			pr_err("%s: %s: hs200 tuning failed (%d)\n",
+				mmc_hostname(host), __func__, err);
+			return err;
+		}
+
+		if (!(host->card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS400)) {
+			pr_debug("%s: card does not support HS400\n",
+				mmc_hostname(host));
+			return 0;
+		}
+	}
+
+	err = mmc_select_hs400(host->card);
+	if (err) {
+		pr_err("%s: %s: select hs400 failed (%d)\n",
+			mmc_hostname(host), __func__, err);
+		return err;
+	}
+
+	return err;
+}
+
+static int mmc_set_clock_bus_speed(struct mmc_card *card, unsigned long freq)
+{
+	int err = 0;
+
+	if (freq == MMC_HS200_MAX_DTR)
+		err = mmc_scale_high(card->host);
+	else
+		err = mmc_scale_low(card->host, freq);
+
+	return err;
+}
+
+static inline unsigned long mmc_ddr_freq_accommodation(unsigned long freq)
+{
+	if (freq == MMC_HIGH_DDR_MAX_DTR)
+		return freq;
+
+	return freq/2;
+}
+
+/**
+ * mmc_change_bus_speed() - Change MMC card bus frequency at runtime
+ * @host: pointer to mmc host structure
+ * @freq: pointer to desired frequency to be set
+ *
+ * Change the MMC card bus frequency at runtime after the card is
+ * initialized. Callers are expected to make sure of the card's
+ * state (DATA/RCV/TRANSFER) before changing the frequency at runtime.
+ *
+ * If the frequency to change is greater than max. supported by card,
+ * *freq is changed to max. supported by card. If it is less than min.
+ * supported by host, *freq is changed to min. supported by host.
+ * Host is assumed to be calimed while calling this funciton.
+ */
+static int mmc_change_bus_speed(struct mmc_host *host, unsigned long *freq)
+{
+	int err = 0;
+	struct mmc_card *card;
+	unsigned long actual_freq;
+
+	card = host->card;
+
+	if (!card || !freq) {
+		err = -EINVAL;
+		goto out;
+	}
+	actual_freq = *freq;
+
+	WARN_ON(!host->claimed);
+
+	/*
+	 * For scaling up/down HS400 we'll need special handling,
+	 * for other timings we can simply do clock frequency change
+	 */
+	if (mmc_card_hs400(card) ||
+		(!mmc_card_hs200(host->card) && *freq == MMC_HS200_MAX_DTR)) {
+		err = mmc_set_clock_bus_speed(card, *freq);
+		if (err) {
+			pr_err("%s: %s: failed (%d)to set bus and clock speed (freq=%lu)\n",
+				mmc_hostname(host), __func__, err, *freq);
+			goto out;
+		}
+	} else if (mmc_card_hs200(host->card)) {
+		mmc_set_clock(host, *freq);
+		err = mmc_hs200_tuning(host->card);
+		if (err) {
+			pr_warn("%s: %s: tuning execution failed %d\n",
+				mmc_hostname(card->host),
+				__func__, err);
+			mmc_set_clock(host, host->clk_scaling.curr_freq);
+		}
+	} else {
+		if (mmc_card_ddr52(host->card))
+			actual_freq = mmc_ddr_freq_accommodation(*freq);
+		mmc_set_clock(host, actual_freq);
+	}
+
+out:
+	return err;
+}
+
+/*
  * Handle the detection and initialisation of a card.
  *
  * In the case of a resume, "oldcard" will contain the card
@@ -1751,6 +1915,16 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
 		}
 	}
 
+	card->clk_scaling_lowest = host->f_min;
+	if ((card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS400) ||
+			(card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200))
+		card->clk_scaling_highest = card->ext_csd.hs200_max_dtr;
+	else if ((card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS) ||
+			(card->mmc_avail_type & EXT_CSD_CARD_TYPE_DDR_52))
+		card->clk_scaling_highest = card->ext_csd.hs_max_dtr;
+	else
+		card->clk_scaling_highest = card->csd.max_dtr;
+
 	/*
 	 * Choose the power class with selected bus interface
 	 */
@@ -1942,6 +2116,7 @@ static int mmc_poweroff_notify(struct mmc_card *card, unsigned int notify_type)
  */
 static void mmc_remove(struct mmc_host *host)
 {
+	mmc_exit_clk_scaling(host);
 	mmc_remove_card(host->card);
 	host->card = NULL;
 }
@@ -2064,6 +2239,13 @@ static int mmc_shutdown(struct mmc_host *host)
 	int err = 0;
 
 	/*
+	 * Exit clock scaling so that it doesn't kick in after
+	 * power off notification is sent
+	 */
+	if (host->caps2 & MMC_CAP2_CLK_SCALE)
+		mmc_exit_clk_scaling(host);
+
+	/*
 	 * In a specific case for poweroff notify, we need to resume the card
 	 * before we can shutdown it properly.
 	 */
@@ -2132,6 +2314,7 @@ static int mmc_can_reset(struct mmc_card *card)
 static int _mmc_hw_reset(struct mmc_host *host)
 {
 	struct mmc_card *card = host->card;
+	int ret;
 
 	/*
 	 * In the case of recovery, we can't expect flushing the cache to work
@@ -2151,7 +2334,15 @@ static int _mmc_hw_reset(struct mmc_host *host)
 		mmc_power_cycle(host, card->ocr);
 		mmc_pwrseq_reset(host);
 	}
-	return mmc_init_card(host, card->ocr, card);
+
+	ret = mmc_init_card(host, card->ocr, card);
+	if (ret) {
+		pr_err("%s: %s: mmc_init_card failed (%d)\n",
+			mmc_hostname(host), __func__, ret);
+		return ret;
+	}
+
+	return ret;
 }
 
 static const struct mmc_bus_ops mmc_ops = {
@@ -2164,6 +2355,7 @@ static int _mmc_hw_reset(struct mmc_host *host)
 	.alive = mmc_alive,
 	.shutdown = mmc_shutdown,
 	.hw_reset = _mmc_hw_reset,
+	.change_bus_speed = mmc_change_bus_speed,
 };
 
 /*
@@ -2220,6 +2412,12 @@ int mmc_attach_mmc(struct mmc_host *host)
 		goto remove_card;
 
 	mmc_claim_host(host);
+	err = mmc_init_clk_scaling(host);
+	if (err) {
+		mmc_release_host(host);
+		goto remove_card;
+	}
+
 	return 0;
 
 remove_card:
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index d0d9f90..40144c1 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -892,7 +892,10 @@ unsigned mmc_sd_get_max_clock(struct mmc_card *card)
 {
 	unsigned max_dtr = (unsigned int)-1;
 
-	if (mmc_card_hs(card)) {
+	if (mmc_card_uhs(card)) {
+		if (max_dtr > card->sw_caps.uhs_max_dtr)
+			max_dtr = card->sw_caps.uhs_max_dtr;
+	} else if (mmc_card_hs(card)) {
 		if (max_dtr > card->sw_caps.hs_max_dtr)
 			max_dtr = card->sw_caps.hs_max_dtr;
 	} else if (max_dtr > card->csd.max_dtr) {
@@ -1059,6 +1062,9 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
 		}
 	}
 
+	card->clk_scaling_highest = mmc_sd_get_max_clock(card);
+	card->clk_scaling_lowest = host->f_min;
+
 	if (host->caps2 & MMC_CAP2_AVOID_3_3V &&
 	    host->ios.signal_voltage == MMC_SIGNAL_VOLTAGE_330) {
 		pr_err("%s: Host failed to negotiate down from 3.3V\n",
@@ -1082,6 +1088,7 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
  */
 static void mmc_sd_remove(struct mmc_host *host)
 {
+	mmc_exit_clk_scaling(host);
 	mmc_remove_card(host->card);
 	host->card = NULL;
 }
@@ -1228,6 +1235,62 @@ static int mmc_sd_hw_reset(struct mmc_host *host)
 	return mmc_sd_init_card(host, host->card->ocr, host->card);
 }
 
+/**
+ * mmc_sd_change_bus_speed() - Change SD card bus frequency at runtime
+ * @host: pointer to mmc host structure
+ * @freq: pointer to desired frequency to be set
+ *
+ * Change the SD card bus frequency at runtime after the card is
+ * initialized. Callers are expected to make sure of the card's
+ * state (DATA/RCV/TRANSFER) beforing changing the frequency at runtime.
+ *
+ * If the frequency to change is greater than max. supported by card,
+ * *freq is changed to max. supported by card and if it is less than min.
+ * supported by host, *freq is changed to min. supported by host.
+ */
+static int mmc_sd_change_bus_speed(struct mmc_host *host, unsigned long *freq)
+{
+	int err = 0;
+	struct mmc_card *card;
+
+	mmc_claim_host(host);
+	/*
+	 * Assign card pointer after claiming host to avoid race
+	 * conditions that may arise during removal of the card.
+	 */
+	card = host->card;
+
+	/* sanity checks */
+	if (!card || !freq) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	mmc_set_clock(host, (unsigned int) (*freq));
+
+	if (!mmc_host_is_spi(card->host) && mmc_card_uhs(card)
+			&& card->host->ops->execute_tuning) {
+		/*
+		 * We try to probe host driver for tuning for any
+		 * frequency, it is host driver responsibility to
+		 * perform actual tuning only when required.
+		 */
+		err = card->host->ops->execute_tuning(card->host,
+				MMC_SEND_TUNING_BLOCK);
+
+		if (err) {
+			pr_warn("%s: %s: tuning execution failed %d. Restoring to previous clock %lu\n",
+				   mmc_hostname(card->host), __func__, err,
+				   host->clk_scaling.curr_freq);
+			mmc_set_clock(host, host->clk_scaling.curr_freq);
+		}
+	}
+
+out:
+	mmc_release_host(host);
+	return err;
+}
+
 static const struct mmc_bus_ops mmc_sd_ops = {
 	.remove = mmc_sd_remove,
 	.detect = mmc_sd_detect,
@@ -1238,6 +1301,7 @@ static int mmc_sd_hw_reset(struct mmc_host *host)
 	.alive = mmc_sd_alive,
 	.shutdown = mmc_sd_suspend,
 	.hw_reset = mmc_sd_hw_reset,
+	.change_bus_speed = mmc_sd_change_bus_speed,
 };
 
 /*
@@ -1292,6 +1356,12 @@ int mmc_attach_sd(struct mmc_host *host)
 		goto remove_card;
 
 	mmc_claim_host(host);
+	err = mmc_init_clk_scaling(host);
+	if (err) {
+		mmc_release_host(host);
+		goto remove_card;
+	}
+
 	return 0;
 
 remove_card:
diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
index b5519a5..e9fe8c6 100644
--- a/drivers/mmc/host/sdhci-msm.c
+++ b/drivers/mmc/host/sdhci-msm.c
@@ -1705,6 +1705,43 @@ static int sdhci_msm_register_vreg(struct sdhci_msm_host *msm_host)
 
 MODULE_DEVICE_TABLE(of, sdhci_msm_dt_match);
 
+int sdhci_msm_dt_get_array(struct device *dev, const char *prop_name,
+				 u32 **out, int *len, u32 size)
+{
+	int ret = 0;
+	struct device_node *np = dev->of_node;
+	size_t sz;
+	u32 *arr = NULL;
+
+	if (!of_get_property(np, prop_name, len)) {
+		ret = -EINVAL;
+		goto out;
+	}
+	sz = *len = *len / sizeof(*arr);
+	if (sz <= 0 || (size > 0 && (sz > size))) {
+		dev_err(dev, "%s invalid size\n", prop_name);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	arr = devm_kzalloc(dev, sz * sizeof(*arr), GFP_KERNEL);
+	if (!arr) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	ret = of_property_read_u32_array(np, prop_name, arr, sz);
+	if (ret < 0) {
+		dev_err(dev, "%s failed reading array %d\n", prop_name, ret);
+		goto out;
+	}
+	*out = arr;
+out:
+	if (ret)
+		*len = 0;
+	return ret;
+}
+
 static const struct sdhci_ops sdhci_msm_ops = {
 	.reset = sdhci_reset,
 	.set_clock = sdhci_msm_set_clock,
diff --git a/drivers/mmc/host/sdhci-pltfm.c b/drivers/mmc/host/sdhci-pltfm.c
index 02bea61..354fc68 100644
--- a/drivers/mmc/host/sdhci-pltfm.c
+++ b/drivers/mmc/host/sdhci-pltfm.c
@@ -36,6 +36,9 @@
 #endif
 #include "sdhci-pltfm.h"
 
+int sdhci_msm_dt_get_array(struct device *dev, const char *prop_name,
+				 u32 **out, int *len, u32 size);
+
 unsigned int sdhci_pltfm_clk_get_max_clock(struct sdhci_host *host)
 {
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -101,6 +104,14 @@ void sdhci_get_of_property(struct platform_device *pdev)
 
 	of_property_read_u32(np, "clock-frequency", &pltfm_host->clock);
 
+	if (sdhci_msm_dt_get_array(&pdev->dev, "qcom,devfreq,freq-table",
+			&host->mmc->clk_scaling.pltfm_freq_table,
+			&host->mmc->clk_scaling.pltfm_freq_table_sz, 0))
+		pr_debug("no clock scaling frequencies were supplied\n");
+	else if (!host->mmc->clk_scaling.pltfm_freq_table ||
+			!host->mmc->clk_scaling.pltfm_freq_table_sz)
+		pr_err("bad dts clock scaling frequencies\n");
+
 	if (of_find_property(np, "keep-power-in-suspend", NULL))
 		host->mmc->pm_caps |= MMC_PM_KEEP_POWER;
 
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 162b9af..f0aafab 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2427,6 +2427,32 @@ static void sdhci_card_event(struct mmc_host *mmc)
 	spin_unlock_irqrestore(&host->lock, flags);
 }
 
+static inline void sdhci_update_power_policy(struct sdhci_host *host,
+		enum sdhci_power_policy policy)
+{
+	host->power_policy = policy;
+}
+
+static int sdhci_notify_load(struct mmc_host *mmc, enum mmc_load state)
+{
+	int err = 0;
+	struct sdhci_host *host = mmc_priv(mmc);
+
+	switch (state) {
+	case MMC_LOAD_HIGH:
+		sdhci_update_power_policy(host, SDHCI_PERFORMANCE_MODE);
+		break;
+	case MMC_LOAD_LOW:
+		sdhci_update_power_policy(host, SDHCI_POWER_SAVE_MODE);
+		break;
+	default:
+		err = -EINVAL;
+		break;
+	}
+
+	return err;
+}
+
 static const struct mmc_host_ops sdhci_ops = {
 	.request	= sdhci_request,
 	.post_req	= sdhci_post_req,
@@ -2441,6 +2467,7 @@ static void sdhci_card_event(struct mmc_host *mmc)
 	.execute_tuning			= sdhci_execute_tuning,
 	.card_event			= sdhci_card_event,
 	.card_busy	= sdhci_card_busy,
+	.notify_load = sdhci_notify_load,
 };
 
 /*****************************************************************************\
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 3b0c97a..740471f 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -346,6 +346,12 @@ enum sdhci_cookie {
 	COOKIE_MAPPED,		/* mapped by sdhci_prepare_data() */
 };
 
+enum sdhci_power_policy {
+	SDHCI_PERFORMANCE_MODE,
+	SDHCI_POWER_SAVE_MODE,
+	SDHCI_POWER_POLICY_NUM /* Always keep this one last */
+};
+
 struct sdhci_host {
 	/* Data set by hardware interface driver */
 	const char *hw_name;	/* Hardware bus name */
@@ -562,6 +568,8 @@ struct sdhci_host {
 	/* Delay (ms) between tuning commands */
 	int			tuning_delay;
 
+	enum sdhci_power_policy power_policy;
+
 	/* Host SDMA buffer boundary. */
 	u32			sdma_boundary;
 
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index de73778..c713581 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -245,6 +245,10 @@ struct mmc_card {
 	struct mmc_host		*host;		/* the host this device belongs to */
 	struct device		dev;		/* the device */
 	u32			ocr;		/* the current OCR setting */
+	unsigned long		clk_scaling_lowest;	/* lowest scaleable*/
+							/* frequency */
+	unsigned long		clk_scaling_highest;	/* highest scaleable */
+
 	unsigned int		rca;		/* relative card address of device */
 	unsigned int		type;		/* card type */
 #define MMC_TYPE_MMC		0		/* MMC card */
@@ -308,6 +312,7 @@ struct mmc_card {
 	unsigned int    nr_parts;
 
 	unsigned int		bouncesz;	/* Bounce buffer size */
+	unsigned int		part_curr;
 };
 
 static inline bool mmc_large_sector(struct mmc_card *card)
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 64300a4..321ab39 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -12,6 +12,7 @@
 
 #include <linux/sched.h>
 #include <linux/device.h>
+#include <linux/devfreq.h>
 #include <linux/fault-inject.h>
 
 #include <linux/mmc/core.h>
@@ -82,6 +83,12 @@ struct mmc_ios {
 
 struct mmc_host;
 
+/* states to represent load on the host */
+enum mmc_load {
+	MMC_LOAD_HIGH,
+	MMC_LOAD_LOW,
+};
+
 struct mmc_host_ops {
 	/*
 	 * It is optional for the host to implement pre_req and post_req in
@@ -161,6 +168,7 @@ struct mmc_host_ops {
 	 */
 	int	(*multi_io_quirk)(struct mmc_card *card,
 				  unsigned int direction, int blk_size);
+	int	(*notify_load)(struct mmc_host *, enum mmc_load);
 };
 
 struct mmc_cqe_ops {
@@ -260,9 +268,60 @@ struct mmc_ctx {
 	struct task_struct *task;
 };
 
+/**
+ * struct mmc_devfeq_clk_scaling - main context for MMC clock scaling logic
+ *
+ * @lock: spinlock to protect statistics
+ * @devfreq: struct that represent mmc-host as a client for devfreq
+ * @devfreq_profile: MMC device profile, mostly polling interval and callbacks
+ * @ondemand_gov_data: struct supplied to ondemmand governor (thresholds)
+ * @state: load state, can be HIGH or LOW. used to notify mmc_host_ops callback
+ * @start_busy: timestamped armed once a data request is started
+ * @measure_interval_start: timestamped armed once a measure interval started
+ * @devfreq_abort: flag to sync between different contexts relevant to devfreq
+ * @skip_clk_scale_freq_update: flag that enable/disable frequency change
+ * @freq_table_sz: table size of frequencies supplied to devfreq
+ * @freq_table: frequencies table supplied to devfreq
+ * @curr_freq: current frequency
+ * @polling_delay_ms: polling interval for status collection used by devfreq
+ * @upthreshold: up-threshold supplied to ondemand governor
+ * @downthreshold: down-threshold supplied to ondemand governor
+ * @need_freq_change: flag indicating if a frequency change is required
+ * @clk_scaling_in_progress: flag indicating if there's ongoing frequency change
+ * @is_busy_started: flag indicating if a request is handled by the HW
+ * @enable: flag indicating if the clock scaling logic is enabled for this host
+ */
+struct mmc_devfeq_clk_scaling {
+	spinlock_t	lock;
+	struct		devfreq *devfreq;
+	struct		devfreq_dev_profile devfreq_profile;
+	struct		devfreq_simple_ondemand_data ondemand_gov_data;
+	enum mmc_load	state;
+	ktime_t		start_busy;
+	ktime_t		measure_interval_start;
+	atomic_t	devfreq_abort;
+	bool		skip_clk_scale_freq_update;
+	int		freq_table_sz;
+	int		pltfm_freq_table_sz;
+	u32		*freq_table;
+	u32		*pltfm_freq_table;
+	unsigned long	total_busy_time_us;
+	unsigned long	target_freq;
+	unsigned long	curr_freq;
+	unsigned long	polling_delay_ms;
+	unsigned int	upthreshold;
+	unsigned int	downthreshold;
+	bool		need_freq_change;
+	bool		clk_scaling_in_progress;
+	bool		is_busy_started;
+	bool		enable;
+};
+
+
 struct mmc_host {
 	struct device		*parent;
 	struct device		class_dev;
+	struct mmc_devfeq_clk_scaling	clk_scaling;
 	int			index;
 	const struct mmc_host_ops *ops;
 	struct mmc_pwrseq	*pwrseq;
@@ -360,6 +419,7 @@ struct mmc_host {
 #define MMC_CAP2_CQE		(1 << 23)	/* Has eMMC command queue engine */
 #define MMC_CAP2_CQE_DCMD	(1 << 24)	/* CQE can issue a direct command */
 #define MMC_CAP2_AVOID_3_3V	(1 << 25)	/* Host must negotiate down from 3.3V */
+#define MMC_CAP2_CLK_SCALE      (1 << 26)       /* Allow dynamic clk scaling */
 
 	int			fixed_drv_type;	/* fixed driver type for non-removable media */
 
@@ -523,6 +583,16 @@ static inline int mmc_regulator_set_vqmmc(struct mmc_host *mmc,
 u32 mmc_vddrange_to_ocrmask(int vdd_min, int vdd_max);
 int mmc_regulator_get_supply(struct mmc_host *mmc);
 
+static inline void mmc_host_clear_sdr104(struct mmc_host *host)
+{
+	host->caps &= ~MMC_CAP_UHS_SDR104;
+}
+
+static inline void mmc_host_set_sdr104(struct mmc_host *host)
+{
+	host->caps |= MMC_CAP_UHS_SDR104;
+}
+
 static inline int mmc_card_is_removable(struct mmc_host *host)
 {
 	return !(host->caps & MMC_CAP_NONREMOVABLE);
