1 files changed, 319 insertions, 13 deletions

diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
index b6f4c1d41636..e0f193f7e3e5 100644
--- a/drivers/mmc/host/sdhci-of-arasan.c
+++ b/drivers/mmc/host/sdhci-of-arasan.c
@@ -19,27 +19,136 @@
  * your option) any later version.
  */
 
+#include <linux/clk-provider.h>
+#include <linux/mfd/syscon.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/phy/phy.h>
+#include <linux/regmap.h>
 #include "sdhci-pltfm.h"
 
 #define SDHCI_ARASAN_CLK_CTRL_OFFSET	0x2c
+#define SDHCI_ARASAN_VENDOR_REGISTER	0x78
 
+#define VENDOR_ENHANCED_STROBE		BIT(0)
 #define CLK_CTRL_TIMEOUT_SHIFT		16
 #define CLK_CTRL_TIMEOUT_MASK		(0xf << CLK_CTRL_TIMEOUT_SHIFT)
 #define CLK_CTRL_TIMEOUT_MIN_EXP	13
 
+/*
+ * On some SoCs the syscon area has a feature where the upper 16-bits of
+ * each 32-bit register act as a write mask for the lower 16-bits.  This allows
+ * atomic updates of the register without locking.  This macro is used on SoCs
+ * that have that feature.
+ */
+#define HIWORD_UPDATE(val, mask, shift) \
+		((val) << (shift) | (mask) << ((shift) + 16))
+
+/**
+ * struct sdhci_arasan_soc_ctl_field - Field used in sdhci_arasan_soc_ctl_map
+ *
+ * @reg:	Offset within the syscon of the register containing this field
+ * @width:	Number of bits for this field
+ * @shift:	Bit offset within @reg of this field (or -1 if not avail)
+ */
+struct sdhci_arasan_soc_ctl_field {
+	u32 reg;
+	u16 width;
+	s16 shift;
+};
+
+/**
+ * struct sdhci_arasan_soc_ctl_map - Map in syscon to corecfg registers
+ *
+ * It's up to the licensee of the Arsan IP block to make these available
+ * somewhere if needed.  Presumably these will be scattered somewhere that's
+ * accessible via the syscon API.
+ *
+ * @baseclkfreq:	Where to find corecfg_baseclkfreq
+ * @hiword_update:	If true, use HIWORD_UPDATE to access the syscon
+ */
+struct sdhci_arasan_soc_ctl_map {
+	struct sdhci_arasan_soc_ctl_field	baseclkfreq;
+	bool					hiword_update;
+};
+
 /**
  * struct sdhci_arasan_data
- * @clk_ahb:	Pointer to the AHB clock
- * @phy: Pointer to the generic phy
+ * @host:		Pointer to the main SDHCI host structure.
+ * @clk_ahb:		Pointer to the AHB clock
+ * @phy:		Pointer to the generic phy
+ * @sdcardclk_hw:	Struct for the clock we might provide to a PHY.
+ * @sdcardclk:		Pointer to normal 'struct clock' for sdcardclk_hw.
+ * @soc_ctl_base:	Pointer to regmap for syscon for soc_ctl registers.
+ * @soc_ctl_map:	Map to get offsets into soc_ctl registers.
  */
 struct sdhci_arasan_data {
+	struct sdhci_host *host;
 	struct clk	*clk_ahb;
 	struct phy	*phy;
+
+	struct clk_hw	sdcardclk_hw;
+	struct clk      *sdcardclk;
+
+	struct regmap	*soc_ctl_base;
+	const struct sdhci_arasan_soc_ctl_map *soc_ctl_map;
+};
+
+static const struct sdhci_arasan_soc_ctl_map rk3399_soc_ctl_map = {
+	.baseclkfreq = { .reg = 0xf000, .width = 8, .shift = 8 },
+	.hiword_update = true,
 };
 
+/**
+ * sdhci_arasan_syscon_write - Write to a field in soc_ctl registers
+ *
+ * This function allows writing to fields in sdhci_arasan_soc_ctl_map.
+ * Note that if a field is specified as not available (shift < 0) then
+ * this function will silently return an error code.  It will be noisy
+ * and print errors for any other (unexpected) errors.
+ *
+ * @host:	The sdhci_host
+ * @fld:	The field to write to
+ * @val:	The value to write
+ */
+static int sdhci_arasan_syscon_write(struct sdhci_host *host,
+				   const struct sdhci_arasan_soc_ctl_field *fld,
+				   u32 val)
+{
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host);
+	struct regmap *soc_ctl_base = sdhci_arasan->soc_ctl_base;
+	u32 reg = fld->reg;
+	u16 width = fld->width;
+	s16 shift = fld->shift;
+	int ret;
+
+	/*
+	 * Silently return errors for shift < 0 so caller doesn't have
+	 * to check for fields which are optional.  For fields that
+	 * are required then caller needs to do something special
+	 * anyway.
+	 */
+	if (shift < 0)
+		return -EINVAL;
+
+	if (sdhci_arasan->soc_ctl_map->hiword_update)
+		ret = regmap_write(soc_ctl_base, reg,
+				   HIWORD_UPDATE(val, GENMASK(width, 0),
+						 shift));
+	else
+		ret = regmap_update_bits(soc_ctl_base, reg,
+					 GENMASK(shift + width, shift),
+					 val << shift);
+
+	/* Yell about (unexpected) regmap errors */
+	if (ret)
+		pr_warn("%s: Regmap write fail: %d\n",
+			 mmc_hostname(host->mmc), ret);
+
+	return ret;
+}
+
 static unsigned int sdhci_arasan_get_timeout_clock(struct sdhci_host *host)
 {
 	u32 div;
@@ -79,6 +188,21 @@ static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock)
 	}
 }
 
+static void sdhci_arasan_hs400_enhanced_strobe(struct mmc_host *mmc,
+					struct mmc_ios *ios)
+{
+	u32 vendor;
+	struct sdhci_host *host = mmc_priv(mmc);
+
+	vendor = readl(host->ioaddr + SDHCI_ARASAN_VENDOR_REGISTER);
+	if (ios->enhanced_strobe)
+		vendor |= VENDOR_ENHANCED_STROBE;
+	else
+		vendor &= ~VENDOR_ENHANCED_STROBE;
+
+	writel(vendor, host->ioaddr + SDHCI_ARASAN_VENDOR_REGISTER);
+}
+
 static struct sdhci_ops sdhci_arasan_ops = {
 	.set_clock = sdhci_arasan_set_clock,
 	.get_max_clock = sdhci_pltfm_clk_get_max_clock,
@@ -172,9 +296,168 @@ static int sdhci_arasan_resume(struct device *dev)
 static SIMPLE_DEV_PM_OPS(sdhci_arasan_dev_pm_ops, sdhci_arasan_suspend,
 			 sdhci_arasan_resume);
 
+static const struct of_device_id sdhci_arasan_of_match[] = {
+	/* SoC-specific compatible strings w/ soc_ctl_map */
+	{
+		.compatible = "rockchip,rk3399-sdhci-5.1",
+		.data = &rk3399_soc_ctl_map,
+	},
+
+	/* Generic compatible below here */
+	{ .compatible = "arasan,sdhci-8.9a" },
+	{ .compatible = "arasan,sdhci-5.1" },
+	{ .compatible = "arasan,sdhci-4.9a" },
+
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, sdhci_arasan_of_match);
+
+/**
+ * sdhci_arasan_sdcardclk_recalc_rate - Return the card clock rate
+ *
+ * Return the current actual rate of the SD card clock.  This can be used
+ * to communicate with out PHY.
+ *
+ * @hw:			Pointer to the hardware clock structure.
+ * @parent_rate		The parent rate (should be rate of clk_xin).
+ * Returns the card clock rate.
+ */
+static unsigned long sdhci_arasan_sdcardclk_recalc_rate(struct clk_hw *hw,
+						      unsigned long parent_rate)
+
+{
+	struct sdhci_arasan_data *sdhci_arasan =
+		container_of(hw, struct sdhci_arasan_data, sdcardclk_hw);
+	struct sdhci_host *host = sdhci_arasan->host;
+
+	return host->mmc->actual_clock;
+}
+
+static const struct clk_ops arasan_sdcardclk_ops = {
+	.recalc_rate = sdhci_arasan_sdcardclk_recalc_rate,
+};
+
+/**
+ * sdhci_arasan_update_baseclkfreq - Set corecfg_baseclkfreq
+ *
+ * The corecfg_baseclkfreq is supposed to contain the MHz of clk_xin.  This
+ * function can be used to make that happen.
+ *
+ * NOTES:
+ * - Many existing devices don't seem to do this and work fine.  To keep
+ *   compatibility for old hardware where the device tree doesn't provide a
+ *   register map, this function is a noop if a soc_ctl_map hasn't been provided
+ *   for this platform.
+ * - It's assumed that clk_xin is not dynamic and that we use the SDHCI divider
+ *   to achieve lower clock rates.  That means that this function is called once
+ *   at probe time and never called again.
+ *
+ * @host:		The sdhci_host
+ */
+static void sdhci_arasan_update_baseclkfreq(struct sdhci_host *host)
+{
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host);
+	const struct sdhci_arasan_soc_ctl_map *soc_ctl_map =
+		sdhci_arasan->soc_ctl_map;
+	u32 mhz = DIV_ROUND_CLOSEST(clk_get_rate(pltfm_host->clk), 1000000);
+
+	/* Having a map is optional */
+	if (!soc_ctl_map)
+		return;
+
+	/* If we have a map, we expect to have a syscon */
+	if (!sdhci_arasan->soc_ctl_base) {
+		pr_warn("%s: Have regmap, but no soc-ctl-syscon\n",
+			mmc_hostname(host->mmc));
+		return;
+	}
+
+	sdhci_arasan_syscon_write(host, &soc_ctl_map->baseclkfreq, mhz);
+}
+
+/**
+ * sdhci_arasan_register_sdclk - Register the sdclk for a PHY to use
+ *
+ * Some PHY devices need to know what the actual card clock is.  In order for
+ * them to find out, we'll provide a clock through the common clock framework
+ * for them to query.
+ *
+ * Note: without seriously re-architecting SDHCI's clock code and testing on
+ * all platforms, there's no way to create a totally beautiful clock here
+ * with all clock ops implemented.  Instead, we'll just create a clock that can
+ * be queried and set the CLK_GET_RATE_NOCACHE attribute to tell common clock
+ * framework that we're doing things behind its back.  This should be sufficient
+ * to create nice clean device tree bindings and later (if needed) we can try
+ * re-architecting SDHCI if we see some benefit to it.
+ *
+ * @sdhci_arasan:	Our private data structure.
+ * @clk_xin:		Pointer to the functional clock
+ * @dev:		Pointer to our struct device.
+ * Returns 0 on success and error value on error
+ */
+static int sdhci_arasan_register_sdclk(struct sdhci_arasan_data *sdhci_arasan,
+				       struct clk *clk_xin,
+				       struct device *dev)
+{
+	struct device_node *np = dev->of_node;
+	struct clk_init_data sdcardclk_init;
+	const char *parent_clk_name;
+	int ret;
+
+	/* Providing a clock to the PHY is optional; no error if missing */
+	if (!of_find_property(np, "#clock-cells", NULL))
+		return 0;
+
+	ret = of_property_read_string_index(np, "clock-output-names", 0,
+					    &sdcardclk_init.name);
+	if (ret) {
+		dev_err(dev, "DT has #clock-cells but no clock-output-names\n");
+		return ret;
+	}
+
+	parent_clk_name = __clk_get_name(clk_xin);
+	sdcardclk_init.parent_names = &parent_clk_name;
+	sdcardclk_init.num_parents = 1;
+	sdcardclk_init.flags = CLK_GET_RATE_NOCACHE;
+	sdcardclk_init.ops = &arasan_sdcardclk_ops;
+
+	sdhci_arasan->sdcardclk_hw.init = &sdcardclk_init;
+	sdhci_arasan->sdcardclk =
+		devm_clk_register(dev, &sdhci_arasan->sdcardclk_hw);
+	sdhci_arasan->sdcardclk_hw.init = NULL;
+
+	ret = of_clk_add_provider(np, of_clk_src_simple_get,
+				  sdhci_arasan->sdcardclk);
+	if (ret)
+		dev_err(dev, "Failed to add clock provider\n");
+
+	return ret;
+}
+
+/**
+ * sdhci_arasan_unregister_sdclk - Undoes sdhci_arasan_register_sdclk()
+ *
+ * Should be called any time we're exiting and sdhci_arasan_register_sdclk()
+ * returned success.
+ *
+ * @dev:		Pointer to our struct device.
+ */
+static void sdhci_arasan_unregister_sdclk(struct device *dev)
+{
+	struct device_node *np = dev->of_node;
+
+	if (!of_find_property(np, "#clock-cells", NULL))
+		return;
+
+	of_clk_del_provider(dev->of_node);
+}
+
 static int sdhci_arasan_probe(struct platform_device *pdev)
 {
 	int ret;
+	const struct of_device_id *match;
+	struct device_node *node;
 	struct clk *clk_xin;
 	struct sdhci_host *host;
 	struct sdhci_pltfm_host *pltfm_host;
@@ -187,6 +470,24 @@ static int sdhci_arasan_probe(struct platform_device *pdev)
 
 	pltfm_host = sdhci_priv(host);
 	sdhci_arasan = sdhci_pltfm_priv(pltfm_host);
+	sdhci_arasan->host = host;
+
+	match = of_match_node(sdhci_arasan_of_match, pdev->dev.of_node);
+	sdhci_arasan->soc_ctl_map = match->data;
+
+	node = of_parse_phandle(pdev->dev.of_node, "arasan,soc-ctl-syscon", 0);
+	if (node) {
+		sdhci_arasan->soc_ctl_base = syscon_node_to_regmap(node);
+		of_node_put(node);
+
+		if (IS_ERR(sdhci_arasan->soc_ctl_base)) {
+			ret = PTR_ERR(sdhci_arasan->soc_ctl_base);
+			if (ret != -EPROBE_DEFER)
+				dev_err(&pdev->dev, "Can't get syscon: %d\n",
+					ret);
+			goto err_pltfm_free;
+		}
+	}
 
 	sdhci_arasan->clk_ahb = devm_clk_get(&pdev->dev, "clk_ahb");
 	if (IS_ERR(sdhci_arasan->clk_ahb)) {
@@ -217,10 +518,16 @@ static int sdhci_arasan_probe(struct platform_device *pdev)
 	sdhci_get_of_property(pdev);
 	pltfm_host->clk = clk_xin;
 
+	sdhci_arasan_update_baseclkfreq(host);
+
+	ret = sdhci_arasan_register_sdclk(sdhci_arasan, clk_xin, &pdev->dev);
+	if (ret)
+		goto clk_disable_all;
+
 	ret = mmc_of_parse(host->mmc);
 	if (ret) {
 		dev_err(&pdev->dev, "parsing dt failed (%u)\n", ret);
-		goto clk_disable_all;
+		goto unreg_clk;
 	}
 
 	sdhci_arasan->phy = ERR_PTR(-ENODEV);
@@ -231,13 +538,13 @@ static int sdhci_arasan_probe(struct platform_device *pdev)
 		if (IS_ERR(sdhci_arasan->phy)) {
 			ret = PTR_ERR(sdhci_arasan->phy);
 			dev_err(&pdev->dev, "No phy for arasan,sdhci-5.1.\n");
-			goto clk_disable_all;
+			goto unreg_clk;
 		}
 
 		ret = phy_init(sdhci_arasan->phy);
 		if (ret < 0) {
 			dev_err(&pdev->dev, "phy_init err.\n");
-			goto clk_disable_all;
+			goto unreg_clk;
 		}
 
 		ret = phy_power_on(sdhci_arasan->phy);
@@ -245,6 +552,9 @@ static int sdhci_arasan_probe(struct platform_device *pdev)
 			dev_err(&pdev->dev, "phy_power_on err.\n");
 			goto err_phy_power;
 		}
+
+		host->mmc_host_ops.hs400_enhanced_strobe =
+					sdhci_arasan_hs400_enhanced_strobe;
 	}
 
 	ret = sdhci_add_host(host);
@@ -259,6 +569,8 @@ err_add_host:
 err_phy_power:
 	if (!IS_ERR(sdhci_arasan->phy))
 		phy_exit(sdhci_arasan->phy);
+unreg_clk:
+	sdhci_arasan_unregister_sdclk(&pdev->dev);
 clk_disable_all:
 	clk_disable_unprepare(clk_xin);
 clk_dis_ahb:
@@ -281,6 +593,8 @@ static int sdhci_arasan_remove(struct platform_device *pdev)
 		phy_exit(sdhci_arasan->phy);
 	}
 
+	sdhci_arasan_unregister_sdclk(&pdev->dev);
+
 	ret = sdhci_pltfm_unregister(pdev);
 
 	clk_disable_unprepare(clk_ahb);
@@ -288,14 +602,6 @@ static int sdhci_arasan_remove(struct platform_device *pdev)
 	return ret;
 }
 
-static const struct of_device_id sdhci_arasan_of_match[] = {
-	{ .compatible = "arasan,sdhci-8.9a" },
-	{ .compatible = "arasan,sdhci-5.1" },
-	{ .compatible = "arasan,sdhci-4.9a" },
-	{ }
-};
-MODULE_DEVICE_TABLE(of, sdhci_arasan_of_match);
-
 static struct platform_driver sdhci_arasan_driver = {
 	.driver = {
 		.name = "sdhci-arasan",