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Subject: Re: [PATCH 2/6] phy: am654-mmc-phy: Add Support for MMC PHY on AM654
 Devices
To:     Ulf Hansson <ulf.hansson@linaro.org>,
        Faiz Abbas <faiz_abbas@ti.com>
CC:     Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        DTML <devicetree@vger.kernel.org>,
        "linux-mmc@vger.kernel.org" <linux-mmc@vger.kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Adrian Hunter <adrian.hunter@intel.com>
References: <20181004111451.9539-1-faiz_abbas@ti.com>
 <20181004111451.9539-3-faiz_abbas@ti.com>
 <CAPDyKFpgUqHy4ihN-NZd8Qiat8K3U7xzofj_yjpDqGiFLd3JGg@mail.gmail.com>
From:   Kishon Vijay Abraham I <kishon@ti.com>
Message-ID: <dfd6f0ee-bfd9-b951-c296-61442a458a24@ti.com>
Date:   Tue, 9 Oct 2018 10:48:19 +0530
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Hi Uffe,

On Monday 08 October 2018 05:02 PM, Ulf Hansson wrote:
> On 4 October 2018 at 13:14, Faiz Abbas <faiz_abbas@ti.com> wrote:
>> Add driver support for the MMC physical layer present
>> on TI's AM654 devices.
>>
>> Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
>> Signed-off-by: Sekhar Nori <nsekhar@ti.com>
> 
> 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@linaro.org>

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@ti.com>");
>> +MODULE_DESCRIPTION("TI AM654 MMC PHY driver");
>> +MODULE_LICENSE("GPL v2");
>> --
>> 2.18.0
>>