Re: [PATCH 2/6] phy: am654-mmc-phy: Add Support for MMC PHY on AM654 Devices

From: Kishon Vijay Abraham I
Date: Tue Oct 09 2018 - 01:23:48 EST


Hi Uffe,

On Monday 08 October 2018 05:02 PM, Ulf Hansson wrote:
> On 4 October 2018 at 13:14, Faiz Abbas <faiz_abbas@xxxxxx> wrote:
>> Add driver support for the MMC physical layer present
>> on TI's AM654 devices.
>>
>> Signed-off-by: Faiz Abbas <faiz_abbas@xxxxxx>
>> Signed-off-by: Sekhar Nori <nsekhar@xxxxxx>
>
> I assume Kishon would like to pick up this through his tree? If not,
> please tell and I can do it, with his ack.

yes, I'll pick this in my tree.

>
> Reviewed-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>

Thanks
Kishon

>
> Kind regards
> Uffe
>
>> ---
>> drivers/phy/ti/Kconfig | 7 +
>> drivers/phy/ti/Makefile | 1 +
>> drivers/phy/ti/phy-am654-mmc.c | 291 +++++++++++++++++++++++++++++++++
>> 3 files changed, 299 insertions(+)
>> create mode 100644 drivers/phy/ti/phy-am654-mmc.c
>>
>> diff --git a/drivers/phy/ti/Kconfig b/drivers/phy/ti/Kconfig
>> index 20503562666c..ea5fe4db01c8 100644
>> --- a/drivers/phy/ti/Kconfig
>> +++ b/drivers/phy/ti/Kconfig
>> @@ -76,3 +76,10 @@ config TWL4030_USB
>> family chips (including the TWL5030 and TPS659x0 devices).
>> This transceiver supports high and full speed devices plus,
>> in host mode, low speed.
>> +
>> +config PHY_AM654_MMC
>> + bool "TI AM654 MMC PHY Support"
>> + select GENERIC_PHY
>> + help
>> + This option enables support for the Physical layer for MMC host
>> + controllers present on TI AM654 SOCs.
>> diff --git a/drivers/phy/ti/Makefile b/drivers/phy/ti/Makefile
>> index 9f361756eaf2..5b2db2d164a5 100644
>> --- a/drivers/phy/ti/Makefile
>> +++ b/drivers/phy/ti/Makefile
>> @@ -6,3 +6,4 @@ obj-$(CONFIG_OMAP_USB2) += phy-omap-usb2.o
>> obj-$(CONFIG_TI_PIPE3) += phy-ti-pipe3.o
>> obj-$(CONFIG_PHY_TUSB1210) += phy-tusb1210.o
>> obj-$(CONFIG_TWL4030_USB) += phy-twl4030-usb.o
>> +obj-$(CONFIG_PHY_AM654_MMC) += phy-am654-mmc.o
>> diff --git a/drivers/phy/ti/phy-am654-mmc.c b/drivers/phy/ti/phy-am654-mmc.c
>> new file mode 100644
>> index 000000000000..91255947fb67
>> --- /dev/null
>> +++ b/drivers/phy/ti/phy-am654-mmc.c
>> @@ -0,0 +1,291 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * phy-am654-mmc.c - MMC PHY 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/of.h>
>> +#include <linux/phy/phy.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/printk.h>
>> +#include <linux/regmap.h>
>> +
>> +/* MMC PHY Registers */
>> +#define PHYCTRL_CTRL1_REG 0x00
>> +#define PHYCTRL_CTRL2_REG 0x04
>> +#define PHYCTRL_CTRL3_REG 0x08
>> +#define PHYCTRL_CTRL4_REG 0x0C
>> +#define PHYCTRL_CTRL5_REG 0x10
>> +#define PHYCTRL_CTRL6_REG 0x14
>> +#define PHYCTRL_STAT1_REG 0x30
>> +#define PHYCTRL_STAT2_REG 0x34
>> +
>> +#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 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
>> +
>> +static struct regmap_config am654_mmc_phy_regmap_config = {
>> + .reg_bits = 32,
>> + .val_bits = 32,
>> + .reg_stride = 4,
>> + .fast_io = true,
>> +};
>> +
>> +struct am654_mmc_phy {
>> + struct regmap *reg_base;
>> + struct clk *mmcclk;
>> + int otap_del_sel;
>> + int trm_icp;
>> + int drv_strength;
>> +};
>> +
>> +static int am654_mmc_phy_init(struct phy *phy)
>> +{
>> + struct am654_mmc_phy *mmc_phy = phy_get_drvdata(phy);
>> + int ret;
>> + u32 val;
>> +
>> + /* Reset registers to default value */
>> + regmap_write(mmc_phy->reg_base, PHYCTRL_CTRL1_REG, 0x10000);
>> + regmap_write(mmc_phy->reg_base, PHYCTRL_CTRL4_REG, 0x0);
>> + regmap_write(mmc_phy->reg_base, PHYCTRL_CTRL5_REG, 0x0);
>> +
>> + /* Calibrate IO lines */
>> + regmap_update_bits(mmc_phy->reg_base, PHYCTRL_CTRL1_REG,
>> + PDB_MASK, PDB_MASK);
>> + ret = regmap_read_poll_timeout(mmc_phy->reg_base, PHYCTRL_STAT1_REG,
>> + val, val & CALDONE_MASK, 1, 20);
>> + if (ret)
>> + return ret;
>> +
>> + /* Enable pins by setting the IO mux to 0 */
>> + regmap_update_bits(mmc_phy->reg_base, PHYCTRL_CTRL1_REG,
>> + IOMUX_ENABLE_MASK, 0);
>> +
>> + mmc_phy->mmcclk = clk_get(&phy->dev, "mmcclk");
>> + if (IS_ERR(mmc_phy->mmcclk)) {
>> + dev_err(&phy->dev, "Error getting mmcclk");
>> + return PTR_ERR(mmc_phy->mmcclk);
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int am654_mmc_phy_exit(struct phy *phy)
>> +{
>> + struct am654_mmc_phy *mmc_phy = phy_get_drvdata(phy);
>> +
>> + clk_put(mmc_phy->mmcclk);
>> +
>> + return 0;
>> +}
>> +
>> +static int am654_mmc_phy_power_on(struct phy *phy)
>> +{
>> + struct am654_mmc_phy *mmc_phy = phy_get_drvdata(phy);
>> + u32 mask, val;
>> + int sel50, sel100;
>> + int rate;
>> +
>> + /* Setup DLL Output TAP delay */
>> + mask = OTAPDLYENA_MASK | OTAPDLYSEL_MASK;
>> + val = (1 << OTAPDLYENA_SHIFT) |
>> + (mmc_phy->otap_del_sel << OTAPDLYSEL_SHIFT);
>> + regmap_update_bits(mmc_phy->reg_base, PHYCTRL_CTRL4_REG,
>> + mask, val);
>> +
>> + rate = clk_get_rate(mmc_phy->mmcclk);
>> + switch (rate) {
>> + 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(mmc_phy->reg_base, PHYCTRL_CTRL5_REG,
>> + mask, val);
>> +
>> + /* Configure DLL TRIM */
>> + mask = DLL_TRIM_ICP_MASK;
>> + val = mmc_phy->trm_icp << DLL_TRIM_ICP_SHIFT;
>> +
>> + /* Configure DLL driver strength */
>> + mask |= DR_TY_MASK;
>> + val |= mmc_phy->drv_strength << DR_TY_SHIFT;
>> + regmap_update_bits(mmc_phy->reg_base, PHYCTRL_CTRL1_REG, mask, val);
>> +
>> + /* Enable DLL */
>> + regmap_update_bits(mmc_phy->reg_base, PHYCTRL_CTRL1_REG,
>> + ENDLL_MASK, 0x1 << ENDLL_SHIFT);
>> +
>> + /*
>> + * Poll for DLL ready. Use a one second timeout.
>> + * Works in all experiments done so far
>> + */
>> + return regmap_read_poll_timeout(mmc_phy->reg_base, PHYCTRL_STAT1_REG,
>> + val, val & DLLRDY_MASK, 1000, 1000000);
>> +
>> +}
>> +
>> +static int am654_mmc_phy_power_off(struct phy *phy)
>> +{
>> + struct am654_mmc_phy *mmc_phy = phy_get_drvdata(phy);
>> +
>> + /* Disable DLL */
>> + regmap_update_bits(mmc_phy->reg_base, PHYCTRL_CTRL1_REG,
>> + ENDLL_MASK, 0);
>> +
>> + /* Reset registers to default value except PDB */
>> + regmap_write(mmc_phy->reg_base, PHYCTRL_CTRL1_REG,
>> + 0x10000 | PDB_MASK);
>> + regmap_write(mmc_phy->reg_base, PHYCTRL_CTRL4_REG, 0x0);
>> + regmap_write(mmc_phy->reg_base, PHYCTRL_CTRL5_REG, 0x0);
>> +
>> + return 0;
>> +}
>> +
>> +static const struct phy_ops ops = {
>> + .init = am654_mmc_phy_init,
>> + .exit = am654_mmc_phy_exit,
>> + .power_on = am654_mmc_phy_power_on,
>> + .power_off = am654_mmc_phy_power_off,
>> + .owner = THIS_MODULE,
>> +};
>> +
>> +static int am654_mmc_phy_probe(struct platform_device *pdev)
>> +{
>> + struct phy_provider *phy_provider;
>> + struct device *dev = &pdev->dev;
>> + struct device_node *np = dev->of_node;
>> + struct am654_mmc_phy *mmc_phy;
>> + struct phy *generic_phy;
>> + struct resource *res;
>> + void __iomem *base;
>> + struct regmap *map;
>> + int drv_strength;
>> + int err;
>> +
>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> + base = devm_ioremap_resource(&pdev->dev, res);
>> + if (IS_ERR(base))
>> + return PTR_ERR(base);
>> +
>> + map = devm_regmap_init_mmio(dev, base, &am654_mmc_phy_regmap_config);
>> + if (IS_ERR(map)) {
>> + dev_err(dev, "could not initialize regmap\n");
>> + return PTR_ERR(map);
>> + }
>> +
>> + mmc_phy = devm_kzalloc(dev, sizeof(struct am654_mmc_phy), GFP_KERNEL);
>> + if (!mmc_phy)
>> + return -ENOMEM;
>> +
>> + mmc_phy->reg_base = map;
>> + err = of_property_read_u32(np, "ti,otap-del-sel",
>> + &mmc_phy->otap_del_sel);
>> + if (err)
>> + return err;
>> +
>> + err = of_property_read_u32(np, "ti,trm-icp",
>> + &mmc_phy->trm_icp);
>> + if (err)
>> + return err;
>> +
>> + err = of_property_read_u32(np, "ti,driver-strength-ohm", &drv_strength);
>> + if (err)
>> + return err;
>> +
>> + switch (drv_strength) {
>> + case 50:
>> + mmc_phy->drv_strength = DRIVER_STRENGTH_50_OHM;
>> + break;
>> + case 33:
>> + mmc_phy->drv_strength = DRIVER_STRENGTH_33_OHM;
>> + break;
>> + case 66:
>> + mmc_phy->drv_strength = DRIVER_STRENGTH_66_OHM;
>> + break;
>> + case 100:
>> + mmc_phy->drv_strength = DRIVER_STRENGTH_100_OHM;
>> + break;
>> + case 40:
>> + mmc_phy->drv_strength = DRIVER_STRENGTH_40_OHM;
>> + break;
>> + default:
>> + dev_err(dev, "Invalid driver strength\n");
>> + return -EINVAL;
>> + }
>> +
>> + generic_phy = devm_phy_create(dev, dev->of_node, &ops);
>> + if (IS_ERR(generic_phy)) {
>> + dev_err(dev, "failed to create PHY\n");
>> + return PTR_ERR(generic_phy);
>> + }
>> +
>> + phy_set_drvdata(generic_phy, mmc_phy);
>> + phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
>> +
>> + return PTR_ERR_OR_ZERO(phy_provider);
>> +}
>> +
>> +static const struct of_device_id am654_mmc_phy_dt_ids[] = {
>> + { .compatible = "ti,am654-mmc-phy" },
>> + {}
>> +};
>> +
>> +MODULE_DEVICE_TABLE(of, am654_mmc_phy_dt_ids);
>> +
>> +static struct platform_driver am654_mmc_phy_driver = {
>> + .probe = am654_mmc_phy_probe,
>> + .driver = {
>> + .name = "am654-mmc-phy",
>> + .of_match_table = am654_mmc_phy_dt_ids,
>> + },
>> +};
>> +
>> +module_platform_driver(am654_mmc_phy_driver);
>> +
>> +MODULE_AUTHOR("Faiz Abbas <faiz_abbas@xxxxxx>");
>> +MODULE_DESCRIPTION("TI AM654 MMC PHY driver");
>> +MODULE_LICENSE("GPL v2");
>> --
>> 2.18.0
>>