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path: root/drivers/mmc/host/sdhci-of-arasan.c
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Diffstat (limited to 'drivers/mmc/host/sdhci-of-arasan.c')
-rw-r--r--drivers/mmc/host/sdhci-of-arasan.c332
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 b6f4c1d41..e0f193f7e 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",