Merge branch 'omap-for-v4.8/legacy' into for-next
[deliverable/linux.git] / drivers / mmc / host / sdhci-of-arasan.c
index b6f4c1d4163624ac5e38dc2caa3e525b8d83d011..e0f193f7e3e50c9f41efe074da079895199b6ca8 100644 (file)
  * 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",
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