Linux-libre 4.4-gnupck-4.4-gnu

1 files changed, 162 insertions, 0 deletions

diff --git a/drivers/mmc/host/dw_mmc-rockchip.c b/drivers/mmc/host/dw_mmc-rockchip.c
index bc76aa224..9becebeec 100644
--- a/drivers/mmc/host/dw_mmc-rockchip.c
+++ b/drivers/mmc/host/dw_mmc-rockchip.c
@@ -13,12 +13,19 @@
 #include <linux/mmc/host.h>
 #include <linux/mmc/dw_mmc.h>
 #include <linux/of_address.h>
+#include <linux/slab.h>
 
 #include "dw_mmc.h"
 #include "dw_mmc-pltfm.h"
 
 #define RK3288_CLKGEN_DIV       2
 
+struct dw_mci_rockchip_priv_data {
+	struct clk		*drv_clk;
+	struct clk		*sample_clk;
+	int			default_sample_phase;
+};
+
 static void dw_mci_rockchip_prepare_command(struct dw_mci *host, u32 *cmdr)
 {
 	*cmdr |= SDMMC_CMD_USE_HOLD_REG;
@@ -33,6 +40,7 @@ static int dw_mci_rk3288_setup_clock(struct dw_mci *host)
 
 static void dw_mci_rk3288_set_ios(struct dw_mci *host, struct mmc_ios *ios)
 {
+	struct dw_mci_rockchip_priv_data *priv = host->priv;
 	int ret;
 	unsigned int cclkin;
 	u32 bus_hz;
@@ -66,6 +74,158 @@ static void dw_mci_rk3288_set_ios(struct dw_mci *host, struct mmc_ios *ios)
 		/* force dw_mci_setup_bus() */
 		host->current_speed = 0;
 	}
+
+	/* Make sure we use phases which we can enumerate with */
+	if (!IS_ERR(priv->sample_clk))
+		clk_set_phase(priv->sample_clk, priv->default_sample_phase);
+}
+
+#define NUM_PHASES			360
+#define TUNING_ITERATION_TO_PHASE(i)	(DIV_ROUND_UP((i) * 360, NUM_PHASES))
+
+static int dw_mci_rk3288_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
+{
+	struct dw_mci *host = slot->host;
+	struct dw_mci_rockchip_priv_data *priv = host->priv;
+	struct mmc_host *mmc = slot->mmc;
+	int ret = 0;
+	int i;
+	bool v, prev_v = 0, first_v;
+	struct range_t {
+		int start;
+		int end; /* inclusive */
+	};
+	struct range_t *ranges;
+	unsigned int range_count = 0;
+	int longest_range_len = -1;
+	int longest_range = -1;
+	int middle_phase;
+
+	if (IS_ERR(priv->sample_clk)) {
+		dev_err(host->dev, "Tuning clock (sample_clk) not defined.\n");
+		return -EIO;
+	}
+
+	ranges = kmalloc_array(NUM_PHASES / 2 + 1, sizeof(*ranges), GFP_KERNEL);
+	if (!ranges)
+		return -ENOMEM;
+
+	/* Try each phase and extract good ranges */
+	for (i = 0; i < NUM_PHASES; ) {
+		clk_set_phase(priv->sample_clk, TUNING_ITERATION_TO_PHASE(i));
+
+		v = !mmc_send_tuning(mmc, opcode, NULL);
+
+		if (i == 0)
+			first_v = v;
+
+		if ((!prev_v) && v) {
+			range_count++;
+			ranges[range_count-1].start = i;
+		}
+		if (v) {
+			ranges[range_count-1].end = i;
+			i++;
+		} else if (i == NUM_PHASES - 1) {
+			/* No extra skipping rules if we're at the end */
+			i++;
+		} else {
+			/*
+			 * No need to check too close to an invalid
+			 * one since testing bad phases is slow.  Skip
+			 * 20 degrees.
+			 */
+			i += DIV_ROUND_UP(20 * NUM_PHASES, 360);
+
+			/* Always test the last one */
+			if (i >= NUM_PHASES)
+				i = NUM_PHASES - 1;
+		}
+
+		prev_v = v;
+	}
+
+	if (range_count == 0) {
+		dev_warn(host->dev, "All phases bad!");
+		ret = -EIO;
+		goto free;
+	}
+
+	/* wrap around case, merge the end points */
+	if ((range_count > 1) && first_v && v) {
+		ranges[0].start = ranges[range_count-1].start;
+		range_count--;
+	}
+
+	if (ranges[0].start == 0 && ranges[0].end == NUM_PHASES - 1) {
+		clk_set_phase(priv->sample_clk, priv->default_sample_phase);
+		dev_info(host->dev, "All phases work, using default phase %d.",
+			 priv->default_sample_phase);
+		goto free;
+	}
+
+	/* Find the longest range */
+	for (i = 0; i < range_count; i++) {
+		int len = (ranges[i].end - ranges[i].start + 1);
+
+		if (len < 0)
+			len += NUM_PHASES;
+
+		if (longest_range_len < len) {
+			longest_range_len = len;
+			longest_range = i;
+		}
+
+		dev_dbg(host->dev, "Good phase range %d-%d (%d len)\n",
+			TUNING_ITERATION_TO_PHASE(ranges[i].start),
+			TUNING_ITERATION_TO_PHASE(ranges[i].end),
+			len
+		);
+	}
+
+	dev_dbg(host->dev, "Best phase range %d-%d (%d len)\n",
+		TUNING_ITERATION_TO_PHASE(ranges[longest_range].start),
+		TUNING_ITERATION_TO_PHASE(ranges[longest_range].end),
+		longest_range_len
+	);
+
+	middle_phase = ranges[longest_range].start + longest_range_len / 2;
+	middle_phase %= NUM_PHASES;
+	dev_info(host->dev, "Successfully tuned phase to %d\n",
+		 TUNING_ITERATION_TO_PHASE(middle_phase));
+
+	clk_set_phase(priv->sample_clk,
+		      TUNING_ITERATION_TO_PHASE(middle_phase));
+
+free:
+	kfree(ranges);
+	return ret;
+}
+
+static int dw_mci_rk3288_parse_dt(struct dw_mci *host)
+{
+	struct device_node *np = host->dev->of_node;
+	struct dw_mci_rockchip_priv_data *priv;
+
+	priv = devm_kzalloc(host->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	if (of_property_read_u32(np, "rockchip,default-sample-phase",
+					&priv->default_sample_phase))
+		priv->default_sample_phase = 0;
+
+	priv->drv_clk = devm_clk_get(host->dev, "ciu-drive");
+	if (IS_ERR(priv->drv_clk))
+		dev_dbg(host->dev, "ciu_drv not available\n");
+
+	priv->sample_clk = devm_clk_get(host->dev, "ciu-sample");
+	if (IS_ERR(priv->sample_clk))
+		dev_dbg(host->dev, "ciu_sample not available\n");
+
+	host->priv = priv;
+
+	return 0;
 }
 
 static int dw_mci_rockchip_init(struct dw_mci *host)
@@ -95,6 +255,8 @@ static const struct dw_mci_drv_data rk3288_drv_data = {
 	.caps			= dw_mci_rk3288_dwmmc_caps,
 	.prepare_command        = dw_mci_rockchip_prepare_command,
 	.set_ios		= dw_mci_rk3288_set_ios,
+	.execute_tuning		= dw_mci_rk3288_execute_tuning,
+	.parse_dt		= dw_mci_rk3288_parse_dt,
 	.setup_clock    = dw_mci_rk3288_setup_clock,
 	.init			= dw_mci_rockchip_init,
 };