[PATCH 3/3] mmc: sdhci_am654: Add Initial Support for AM654 SDHCI driver

From: Faiz Abbas
Date: Thu Nov 29 2018 - 11:12:56 EST


The host controllers on TI's AM654 SOCs are not compatible with
the phy and consumer model of the sdhci-of-arasan driver. It turns out
that for optimal operation at higher speeds, a special tuning procedure
needs to be implemented which involves configuration of platform
specific phy registers.

Therefore, branch out to a new sdhci_am654 driver and add the phy
register space with all phy configurations to it. Populate AM654
specific callbacks to sdhci_ops and add SDHCI_QUIRKS wherever
applicable.

Only add support for upto High Speed for SD card and upto DDR52 speed
mode for eMMC. Higher speeds will be added in subsequent patches.

Signed-off-by: Faiz Abbas <faiz_abbas@xxxxxx>
---
drivers/mmc/host/Kconfig | 12 +
drivers/mmc/host/Makefile | 1 +
drivers/mmc/host/sdhci-of-arasan.c | 46 ----
drivers/mmc/host/sdhci_am654.c | 376 +++++++++++++++++++++++++++++
4 files changed, 389 insertions(+), 46 deletions(-)
create mode 100644 drivers/mmc/host/sdhci_am654.c

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 1b58739d9744..cfb2eb1a2c32 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -977,3 +977,15 @@ config MMC_SDHCI_OMAP
If you have a controller with this interface, say Y or M here.

If unsure, say N.
+
+config MMC_SDHCI_AM654
+ tristate "Support for the SDHCI Controller in TI's AM654 SOCs"
+ depends on MMC_SDHCI_PLTFM && OF
+ help
+ This selects the Secure Digital Host Controller Interface (SDHCI)
+ support present in TI's AM654 SOCs. The controller supports
+ SD/MMC/SDIO devices.
+
+ If you have a controller with this interface, say Y or M here.
+
+ If unsure, say N.
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index 720d37777098..5c7770edc431 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -22,6 +22,7 @@ obj-$(CONFIG_MMC_SDHCI_S3C) += sdhci-s3c.o
obj-$(CONFIG_MMC_SDHCI_SIRF) += sdhci-sirf.o
obj-$(CONFIG_MMC_SDHCI_F_SDH30) += sdhci_f_sdh30.o
obj-$(CONFIG_MMC_SDHCI_SPEAR) += sdhci-spear.o
+obj-$(CONFIG_MMC_SDHCI_AM654) += sdhci_am654.o
obj-$(CONFIG_MMC_WBSD) += wbsd.o
obj-$(CONFIG_MMC_AU1X) += au1xmmc.o
obj-$(CONFIG_MMC_MTK) += mtk-sd.o
diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
index 142c4b802f31..c9e3e050ccc8 100644
--- a/drivers/mmc/host/sdhci-of-arasan.c
+++ b/drivers/mmc/host/sdhci-of-arasan.c
@@ -231,25 +231,6 @@ static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock)
}
}

-static void sdhci_arasan_am654_set_clock(struct sdhci_host *host,
- unsigned int clock)
-{
- struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
- struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host);
-
- if (sdhci_arasan->is_phy_on) {
- phy_power_off(sdhci_arasan->phy);
- sdhci_arasan->is_phy_on = false;
- }
-
- sdhci_set_clock(host, clock);
-
- if (clock > PHY_CLK_TOO_SLOW_HZ) {
- phy_power_on(sdhci_arasan->phy);
- sdhci_arasan->is_phy_on = true;
- }
-}
-
static void sdhci_arasan_hs400_enhanced_strobe(struct mmc_host *mmc,
struct mmc_ios *ios)
{
@@ -335,29 +316,6 @@ static struct sdhci_arasan_of_data sdhci_arasan_data = {
.pdata = &sdhci_arasan_pdata,
};

-static const struct sdhci_ops sdhci_arasan_am654_ops = {
- .set_clock = sdhci_arasan_am654_set_clock,
- .get_max_clock = sdhci_pltfm_clk_get_max_clock,
- .get_timeout_clock = sdhci_pltfm_clk_get_max_clock,
- .set_bus_width = sdhci_set_bus_width,
- .reset = sdhci_arasan_reset,
- .set_uhs_signaling = sdhci_set_uhs_signaling,
-};
-
-static const struct sdhci_pltfm_data sdhci_arasan_am654_pdata = {
- .ops = &sdhci_arasan_am654_ops,
- .quirks = SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN |
- SDHCI_QUIRK_INVERTED_WRITE_PROTECT |
- SDHCI_QUIRK_MULTIBLOCK_READ_ACMD12,
- .quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN |
- SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN |
- SDHCI_QUIRK2_CAPS_BIT63_FOR_HS400,
-};
-
-static const struct sdhci_arasan_of_data sdhci_arasan_am654_data = {
- .pdata = &sdhci_arasan_am654_pdata,
-};
-
static u32 sdhci_arasan_cqhci_irq(struct sdhci_host *host, u32 intmask)
{
int cmd_error = 0;
@@ -520,10 +478,6 @@ static const struct of_device_id sdhci_arasan_of_match[] = {
.compatible = "rockchip,rk3399-sdhci-5.1",
.data = &sdhci_arasan_rk3399_data,
},
- {
- .compatible = "ti,am654-sdhci-5.1",
- .data = &sdhci_arasan_am654_data,
- },
/* Generic compatible below here */
{
.compatible = "arasan,sdhci-8.9a",
diff --git a/drivers/mmc/host/sdhci_am654.c b/drivers/mmc/host/sdhci_am654.c
new file mode 100644
index 000000000000..6e5be12d5946
--- /dev/null
+++ b/drivers/mmc/host/sdhci_am654.c
@@ -0,0 +1,376 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * sdhci_am654.c - SDHCI driver for TI's AM654 SOCs
+ *
+ * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com
+ *
+ */
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/pm_runtime.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+
+#include "sdhci-pltfm.h"
+
+/* CTL_CFG Registers */
+#define CTL_CFG_2 0x14
+
+#define SLOTTYPE_MASK GENMASK(31, 30)
+#define SLOTTYPE_EMBEDDED BIT(30)
+
+/* PHY Registers */
+#define PHY_CTRL1 0x100
+#define PHY_CTRL2 0x104
+#define PHY_CTRL3 0x108
+#define PHY_CTRL4 0x10C
+#define PHY_CTRL5 0x110
+#define PHY_CTRL6 0x114
+#define PHY_STAT1 0x130
+#define PHY_STAT2 0x134
+
+#define IOMUX_ENABLE_SHIFT 31
+#define IOMUX_ENABLE_MASK BIT(IOMUX_ENABLE_SHIFT)
+#define OTAPDLYENA_SHIFT 20
+#define OTAPDLYENA_MASK BIT(OTAPDLYENA_SHIFT)
+#define OTAPDLYSEL_SHIFT 12
+#define OTAPDLYSEL_MASK GENMASK(15, 12)
+#define STRBSEL_SHIFT 24
+#define STRBSEL_MASK GENMASK(27, 24)
+#define SEL50_SHIFT 8
+#define SEL50_MASK BIT(SEL50_SHIFT)
+#define SEL100_SHIFT 9
+#define SEL100_MASK BIT(SEL100_SHIFT)
+#define DLL_TRIM_ICP_SHIFT 4
+#define DLL_TRIM_ICP_MASK GENMASK(7, 4)
+#define DR_TY_SHIFT 20
+#define DR_TY_MASK GENMASK(22, 20)
+#define ENDLL_SHIFT 1
+#define ENDLL_MASK BIT(ENDLL_SHIFT)
+#define DLLRDY_SHIFT 0
+#define DLLRDY_MASK BIT(DLLRDY_SHIFT)
+#define PDB_SHIFT 0
+#define PDB_MASK BIT(PDB_SHIFT)
+#define CALDONE_SHIFT 1
+#define CALDONE_MASK BIT(CALDONE_SHIFT)
+#define RETRIM_SHIFT 17
+#define RETRIM_MASK BIT(RETRIM_SHIFT)
+
+#define DRIVER_STRENGTH_50_OHM 0x0
+#define DRIVER_STRENGTH_33_OHM 0x1
+#define DRIVER_STRENGTH_66_OHM 0x2
+#define DRIVER_STRENGTH_100_OHM 0x3
+#define DRIVER_STRENGTH_40_OHM 0x4
+
+#define CLOCK_TOO_SLOW_HZ 400000
+
+static struct regmap_config sdhci_am654_regmap_config = {
+ .reg_bits = 32,
+ .val_bits = 32,
+ .reg_stride = 4,
+ .fast_io = true,
+};
+
+struct sdhci_am654_data {
+ struct regmap *base;
+ struct clk *clk_ahb;
+ int otap_del_sel;
+ int trm_icp;
+ int drv_strength;
+ bool dll_on;
+};
+
+static void sdhci_am654_set_clock(struct sdhci_host *host, unsigned int clock)
+{
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct sdhci_am654_data *sdhci_am654 = sdhci_pltfm_priv(pltfm_host);
+ int sel50, sel100;
+ u32 mask, val;
+ int ret;
+
+ if (sdhci_am654->dll_on) {
+ regmap_update_bits(sdhci_am654->base, PHY_CTRL1,
+ ENDLL_MASK, 0);
+
+ sdhci_am654->dll_on = false;
+ }
+
+ sdhci_set_clock(host, clock);
+
+ if (clock > CLOCK_TOO_SLOW_HZ) {
+ /* Setup DLL Output TAP delay */
+ mask = OTAPDLYENA_MASK | OTAPDLYSEL_MASK;
+ val = (1 << OTAPDLYENA_SHIFT) |
+ (sdhci_am654->otap_del_sel << OTAPDLYSEL_SHIFT);
+ regmap_update_bits(sdhci_am654->base, PHY_CTRL4,
+ mask, val);
+ switch (clock) {
+ case 200000000:
+ sel50 = 0;
+ sel100 = 0;
+ break;
+ case 100000000:
+ sel50 = 0;
+ sel100 = 1;
+ break;
+ default:
+ sel50 = 1;
+ sel100 = 0;
+ }
+
+ /* Configure PHY DLL frequency */
+ mask = SEL50_MASK | SEL100_MASK;
+ val = (sel50 << SEL50_SHIFT) | (sel100 << SEL100_SHIFT);
+ regmap_update_bits(sdhci_am654->base, PHY_CTRL5,
+ mask, val);
+ /* Configure DLL TRIM */
+ mask = DLL_TRIM_ICP_MASK;
+ val = sdhci_am654->trm_icp << DLL_TRIM_ICP_SHIFT;
+
+ /* Configure DLL driver strength */
+ mask |= DR_TY_MASK;
+ val |= sdhci_am654->drv_strength << DR_TY_SHIFT;
+ regmap_update_bits(sdhci_am654->base, PHY_CTRL1,
+ mask, val);
+ /* Enable DLL */
+ regmap_update_bits(sdhci_am654->base, PHY_CTRL1,
+ ENDLL_MASK, 0x1 << ENDLL_SHIFT);
+ /*
+ * Poll for DLL ready. Use a one second timeout.
+ * Works in all experiments done so far
+ */
+ ret = regmap_read_poll_timeout(sdhci_am654->base,
+ PHY_STAT1, val,
+ val & DLLRDY_MASK,
+ 1000, 1000000);
+
+ sdhci_am654->dll_on = true;
+ }
+}
+
+
+static void sdhci_am654_set_power(struct sdhci_host *host, unsigned char mode,
+ unsigned short vdd)
+{
+ if (!IS_ERR(host->mmc->supply.vmmc)) {
+ struct mmc_host *mmc = host->mmc;
+
+ mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd);
+ }
+ sdhci_set_power_noreg(host, mode, vdd);
+}
+
+struct sdhci_ops sdhci_am654_ops = {
+ .get_max_clock = sdhci_pltfm_clk_get_max_clock,
+ .get_timeout_clock = sdhci_pltfm_clk_get_max_clock,
+ .set_uhs_signaling = sdhci_set_uhs_signaling,
+ .set_bus_width = sdhci_set_bus_width,
+ .set_power = sdhci_am654_set_power,
+ .set_clock = sdhci_am654_set_clock,
+ .reset = sdhci_reset,
+};
+
+static const struct sdhci_pltfm_data sdhci_am654_pdata = {
+ .ops = &sdhci_am654_ops,
+ .quirks = SDHCI_QUIRK_INVERTED_WRITE_PROTECT |
+ SDHCI_QUIRK_MULTIBLOCK_READ_ACMD12,
+ .quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
+};
+
+static int sdhci_am654_init(struct sdhci_host *host)
+{
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct sdhci_am654_data *sdhci_am654 = sdhci_pltfm_priv(pltfm_host);
+ u32 ctl_cfg_2 = 0;
+ u32 val;
+ int ret;
+
+ regmap_read(sdhci_am654->base, PHY_STAT1, &val);
+ if (~val & CALDONE_MASK) {
+ /* Calibrate IO lines */
+ regmap_update_bits(sdhci_am654->base, PHY_CTRL1,
+ PDB_MASK, PDB_MASK);
+ ret = regmap_read_poll_timeout(sdhci_am654->base, PHY_STAT1,
+ val, val & CALDONE_MASK, 1, 20);
+ if (ret)
+ return ret;
+ }
+
+ /* Enable pins by setting IO mux to 0 */
+ regmap_update_bits(sdhci_am654->base, PHY_CTRL1,
+ IOMUX_ENABLE_MASK, 0);
+
+ /* Set slot type based on SD or eMMC */
+ if (host->mmc->caps & MMC_CAP_NONREMOVABLE)
+ ctl_cfg_2 = SLOTTYPE_EMBEDDED;
+
+ regmap_update_bits(sdhci_am654->base, CTL_CFG_2,
+ ctl_cfg_2, SLOTTYPE_MASK);
+
+ return sdhci_add_host(host);
+}
+
+static int sdhci_am654_get_of_property(struct platform_device *pdev,
+ struct sdhci_am654_data *sdhci_am654)
+{
+ struct device *dev = &pdev->dev;
+ int drv_strength;
+ int ret;
+
+ ret = device_property_read_u32(dev, "ti,trm-icp",
+ &sdhci_am654->trm_icp);
+ if (ret)
+ return ret;
+
+ ret = device_property_read_u32(dev, "ti,otap-del-sel",
+ &sdhci_am654->otap_del_sel);
+ if (ret)
+ return ret;
+
+ ret = device_property_read_u32(dev, "ti,driver-strength-ohm",
+ &drv_strength);
+ if (ret)
+ return ret;
+
+ switch (drv_strength) {
+ case 50:
+ sdhci_am654->drv_strength = DRIVER_STRENGTH_50_OHM;
+ break;
+ case 33:
+ sdhci_am654->drv_strength = DRIVER_STRENGTH_33_OHM;
+ break;
+ case 66:
+ sdhci_am654->drv_strength = DRIVER_STRENGTH_66_OHM;
+ break;
+ case 100:
+ sdhci_am654->drv_strength = DRIVER_STRENGTH_100_OHM;
+ break;
+ case 40:
+ sdhci_am654->drv_strength = DRIVER_STRENGTH_40_OHM;
+ break;
+ default:
+ dev_err(dev, "Invalid driver strength\n");
+ return -EINVAL;
+ }
+
+ sdhci_get_of_property(pdev);
+
+ return 0;
+}
+
+static int sdhci_am654_probe(struct platform_device *pdev)
+{
+ struct sdhci_pltfm_host *pltfm_host;
+ struct sdhci_am654_data *sdhci_am654;
+ struct sdhci_host *host;
+ struct resource *res;
+ struct clk *clk_xin;
+ struct device *dev = &pdev->dev;
+ void __iomem *base;
+ int ret;
+
+ host = sdhci_pltfm_init(pdev, &sdhci_am654_pdata, sizeof(*sdhci_am654));
+ if (IS_ERR(host))
+ return PTR_ERR(host);
+
+ pltfm_host = sdhci_priv(host);
+ sdhci_am654 = sdhci_pltfm_priv(pltfm_host);
+
+ clk_xin = devm_clk_get(dev, "clk_xin");
+ if (IS_ERR(clk_xin)) {
+ dev_err(dev, "clk_xin clock not found.\n");
+ ret = PTR_ERR(clk_xin);
+ goto err_pltfm_free;
+ }
+
+ sdhci_am654->clk_ahb = devm_clk_get(dev, "clk_ahb");
+ if (IS_ERR(sdhci_am654->clk_ahb)) {
+ dev_err(dev, "clk_ahb clock not found.\n");
+ ret = PTR_ERR(sdhci_am654->clk_ahb);
+ goto err_pltfm_free;
+ }
+
+ pltfm_host->clk = clk_xin;
+
+ pm_runtime_enable(dev);
+ ret = pm_runtime_get_sync(dev);
+ if (ret > 0) {
+ pm_runtime_put_noidle(dev);
+ goto pm_runtime_disable;
+ }
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+ base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(base)) {
+ ret = PTR_ERR(base);
+ goto pm_runtime_put;
+ }
+
+ sdhci_am654->base = devm_regmap_init_mmio(dev, base,
+ &sdhci_am654_regmap_config);
+ if (IS_ERR(sdhci_am654->base)) {
+ dev_err(dev, "Failed to initialize regmap\n");
+ ret = PTR_ERR(sdhci_am654->base);
+ goto pm_runtime_put;
+ }
+
+ ret = sdhci_am654_get_of_property(pdev, sdhci_am654);
+ if (ret)
+ goto pm_runtime_put;
+
+ ret = mmc_of_parse(host->mmc);
+ if (ret) {
+ dev_err(dev, "parsing dt failed (%d)\n", ret);
+ goto pm_runtime_put;
+ }
+
+ ret = sdhci_am654_init(host);
+ if (ret)
+ goto pm_runtime_put;
+
+ return 0;
+
+pm_runtime_put:
+ pm_runtime_put_sync(dev);
+pm_runtime_disable:
+ pm_runtime_disable(dev);
+err_pltfm_free:
+ sdhci_pltfm_free(pdev);
+ return ret;
+}
+
+static int sdhci_am654_remove(struct platform_device *pdev)
+{
+ struct sdhci_host *host = platform_get_drvdata(pdev);
+ int ret;
+
+ sdhci_remove_host(host, true);
+ ret = pm_runtime_put_sync(&pdev->dev);
+ if (ret < 0)
+ return ret;
+
+ pm_runtime_disable(&pdev->dev);
+ sdhci_pltfm_free(pdev);
+
+ return 0;
+}
+
+static const struct of_device_id sdhci_am654_of_match[] = {
+ { .compatible = "ti,am654-sdhci-5.1" },
+ { /* sentinel */ }
+};
+
+static struct platform_driver sdhci_am654_driver = {
+ .driver = {
+ .name = "sdhci-am654",
+ .of_match_table = sdhci_am654_of_match,
+ },
+ .probe = sdhci_am654_probe,
+ .remove = sdhci_am654_remove,
+};
+
+module_platform_driver(sdhci_am654_driver);
+
+MODULE_DESCRIPTION("Driver for SDHCI Controller on TI's AM654 devices");
+MODULE_AUTHOR("Faiz Abbas <faiz_abbas@xxxxxx>");
+MODULE_LICENSE("GPL");
--
2.19.2