Re: [PATCH v6 2/2] phy: add a driver for the Rockchip SoC internal PCIe PHY

From: Kishon Vijay Abraham I
Date: Fri Sep 02 2016 - 08:21:08 EST




On Thursday 01 September 2016 01:14 PM, Shawn Lin wrote:
> This patch to add a generic PHY driver for rockchip PCIe PHY.
> Access the PHY via registers provided by GRF (general register
> files) module.
>
> Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>

merged, thanks

-Kishon
>
> ---
>
> Changes in v6:
> - use dev_* instead of pr_*
>
> Changes in v5:
> - add COMPILE_TEST and select MFD_SYSCON on Kconfig
>
> Changes in v4:
> - remove laneoff symbol as we still fail to get a workable solution
> except for exporting symbol. But I will be back with some other possible
> routine once finished.
>
> Changes in v3: None
> Changes in v2: None
>
> drivers/phy/Kconfig | 8 +
> drivers/phy/Makefile | 1 +
> drivers/phy/phy-rockchip-pcie.c | 357 ++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 366 insertions(+)
> create mode 100644 drivers/phy/phy-rockchip-pcie.c
>
> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
> index f9bf981..46e5536 100644
> --- a/drivers/phy/Kconfig
> +++ b/drivers/phy/Kconfig
> @@ -388,6 +388,14 @@ config PHY_ROCKCHIP_DP
> help
> Enable this to support the Rockchip Display Port PHY.
>
> +config PHY_ROCKCHIP_PCIE
> + tristate "Rockchip PCIe PHY Driver"
> + depends on (ARCH_ROCKCHIP && OF) || COMPILE_TEST
> + select GENERIC_PHY
> + select MFD_SYSCON
> + help
> + Enable this to support the Rockchip PCIe PHY.
> +
> config PHY_ST_SPEAR1310_MIPHY
> tristate "ST SPEAR1310-MIPHY driver"
> select GENERIC_PHY
> diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
> index 74b44ef..ce0e526 100644
> --- a/drivers/phy/Makefile
> +++ b/drivers/phy/Makefile
> @@ -42,6 +42,7 @@ obj-$(CONFIG_PHY_QCOM_APQ8064_SATA) += phy-qcom-apq8064-sata.o
> obj-$(CONFIG_PHY_ROCKCHIP_USB) += phy-rockchip-usb.o
> obj-$(CONFIG_PHY_ROCKCHIP_INNO_USB2) += phy-rockchip-inno-usb2.o
> obj-$(CONFIG_PHY_ROCKCHIP_EMMC) += phy-rockchip-emmc.o
> +obj-$(CONFIG_PHY_ROCKCHIP_PCIE) += phy-rockchip-pcie.o
> obj-$(CONFIG_PHY_ROCKCHIP_DP) += phy-rockchip-dp.o
> obj-$(CONFIG_PHY_QCOM_IPQ806X_SATA) += phy-qcom-ipq806x-sata.o
> obj-$(CONFIG_PHY_ST_SPEAR1310_MIPHY) += phy-spear1310-miphy.o
> diff --git a/drivers/phy/phy-rockchip-pcie.c b/drivers/phy/phy-rockchip-pcie.c
> new file mode 100644
> index 0000000..a2b4c6b
> --- /dev/null
> +++ b/drivers/phy/phy-rockchip-pcie.c
> @@ -0,0 +1,357 @@
> +/*
> + * Rockchip PCIe PHY driver
> + *
> + * Copyright (C) 2016 Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
> + * Copyright (C) 2016 ROCKCHIP, Inc.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/of_platform.h>
> +#include <linux/phy/phy.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/reset.h>
> +
> +/*
> + * The higher 16-bit of this register is used for write protection
> + * only if BIT(x + 16) set to 1 the BIT(x) can be written.
> + */
> +#define HIWORD_UPDATE(val, mask, shift) \
> + ((val) << (shift) | (mask) << ((shift) + 16))
> +
> +#define PHY_MAX_LANE_NUM 4
> +#define PHY_CFG_DATA_SHIFT 7
> +#define PHY_CFG_ADDR_SHIFT 1
> +#define PHY_CFG_DATA_MASK 0xf
> +#define PHY_CFG_ADDR_MASK 0x3f
> +#define PHY_CFG_RD_MASK 0x3ff
> +#define PHY_CFG_WR_ENABLE 1
> +#define PHY_CFG_WR_DISABLE 1
> +#define PHY_CFG_WR_SHIFT 0
> +#define PHY_CFG_WR_MASK 1
> +#define PHY_CFG_PLL_LOCK 0x10
> +#define PHY_CFG_CLK_TEST 0x10
> +#define PHY_CFG_CLK_SCC 0x12
> +#define PHY_CFG_SEPE_RATE BIT(3)
> +#define PHY_CFG_PLL_100M BIT(3)
> +#define PHY_PLL_LOCKED BIT(9)
> +#define PHY_PLL_OUTPUT BIT(10)
> +#define PHY_LANE_A_STATUS 0x30
> +#define PHY_LANE_B_STATUS 0x31
> +#define PHY_LANE_C_STATUS 0x32
> +#define PHY_LANE_D_STATUS 0x33
> +#define PHY_LANE_RX_DET_SHIFT 11
> +#define PHY_LANE_RX_DET_TH 0x1
> +#define PHY_LANE_IDLE_OFF 0x1
> +#define PHY_LANE_IDLE_MASK 0x1
> +#define PHY_LANE_IDLE_A_SHIFT 3
> +#define PHY_LANE_IDLE_B_SHIFT 4
> +#define PHY_LANE_IDLE_C_SHIFT 5
> +#define PHY_LANE_IDLE_D_SHIFT 6
> +
> +struct rockchip_pcie_data {
> + unsigned int pcie_conf;
> + unsigned int pcie_status;
> + unsigned int pcie_laneoff;
> +};
> +
> +struct rockchip_pcie_phy {
> + struct rockchip_pcie_data *phy_data;
> + struct regmap *reg_base;
> + struct reset_control *phy_rst;
> + struct clk *clk_pciephy_ref;
> +};
> +
> +static inline void phy_wr_cfg(struct rockchip_pcie_phy *rk_phy,
> + u32 addr, u32 data)
> +{
> + regmap_write(rk_phy->reg_base, rk_phy->phy_data->pcie_conf,
> + HIWORD_UPDATE(data,
> + PHY_CFG_DATA_MASK,
> + PHY_CFG_DATA_SHIFT) |
> + HIWORD_UPDATE(addr,
> + PHY_CFG_ADDR_MASK,
> + PHY_CFG_ADDR_SHIFT));
> + udelay(1);
> + regmap_write(rk_phy->reg_base, rk_phy->phy_data->pcie_conf,
> + HIWORD_UPDATE(PHY_CFG_WR_ENABLE,
> + PHY_CFG_WR_MASK,
> + PHY_CFG_WR_SHIFT));
> + udelay(1);
> + regmap_write(rk_phy->reg_base, rk_phy->phy_data->pcie_conf,
> + HIWORD_UPDATE(PHY_CFG_WR_DISABLE,
> + PHY_CFG_WR_MASK,
> + PHY_CFG_WR_SHIFT));
> +}
> +
> +static inline u32 phy_rd_cfg(struct rockchip_pcie_phy *rk_phy,
> + u32 addr)
> +{
> + u32 val;
> +
> + regmap_write(rk_phy->reg_base, rk_phy->phy_data->pcie_conf,
> + HIWORD_UPDATE(addr,
> + PHY_CFG_RD_MASK,
> + PHY_CFG_ADDR_SHIFT));
> + regmap_read(rk_phy->reg_base,
> + rk_phy->phy_data->pcie_status,
> + &val);
> + return val;
> +}
> +
> +static int rockchip_pcie_phy_power_off(struct phy *phy)
> +{
> + struct rockchip_pcie_phy *rk_phy = phy_get_drvdata(phy);
> + int err = 0;
> +
> + err = reset_control_assert(rk_phy->phy_rst);
> + if (err) {
> + dev_err(&phy->dev, "assert phy_rst err %d\n", err);
> + return err;
> + }
> +
> + return 0;
> +}
> +
> +static int rockchip_pcie_phy_power_on(struct phy *phy)
> +{
> + struct rockchip_pcie_phy *rk_phy = phy_get_drvdata(phy);
> + int err = 0;
> + u32 status;
> + unsigned long timeout;
> +
> + err = reset_control_deassert(rk_phy->phy_rst);
> + if (err) {
> + dev_err(&phy->dev, "deassert phy_rst err %d\n", err);
> + return err;
> + }
> +
> + regmap_write(rk_phy->reg_base, rk_phy->phy_data->pcie_conf,
> + HIWORD_UPDATE(PHY_CFG_PLL_LOCK,
> + PHY_CFG_ADDR_MASK,
> + PHY_CFG_ADDR_SHIFT));
> +
> + /*
> + * No documented timeout value for phy operation below,
> + * so we make it large enough here. And we use loop-break
> + * method which should not be harmful.
> + */
> + timeout = jiffies + msecs_to_jiffies(1000);
> +
> + err = -EINVAL;
> + while (time_before(jiffies, timeout)) {
> + regmap_read(rk_phy->reg_base,
> + rk_phy->phy_data->pcie_status,
> + &status);
> + if (status & PHY_PLL_LOCKED) {
> + dev_dbg(&phy->dev, "pll locked!\n");
> + err = 0;
> + break;
> + }
> + msleep(20);
> + }
> +
> + if (err) {
> + dev_err(&phy->dev, "pll lock timeout!\n");
> + goto err_pll_lock;
> + }
> +
> + phy_wr_cfg(rk_phy, PHY_CFG_CLK_TEST, PHY_CFG_SEPE_RATE);
> + phy_wr_cfg(rk_phy, PHY_CFG_CLK_SCC, PHY_CFG_PLL_100M);
> +
> + err = -ETIMEDOUT;
> + while (time_before(jiffies, timeout)) {
> + regmap_read(rk_phy->reg_base,
> + rk_phy->phy_data->pcie_status,
> + &status);
> + if (!(status & PHY_PLL_OUTPUT)) {
> + dev_dbg(&phy->dev, "pll output enable done!\n");
> + err = 0;
> + break;
> + }
> + msleep(20);
> + }
> +
> + if (err) {
> + dev_err(&phy->dev, "pll output enable timeout!\n");
> + goto err_pll_lock;
> + }
> +
> + regmap_write(rk_phy->reg_base, rk_phy->phy_data->pcie_conf,
> + HIWORD_UPDATE(PHY_CFG_PLL_LOCK,
> + PHY_CFG_ADDR_MASK,
> + PHY_CFG_ADDR_SHIFT));
> + err = -EINVAL;
> + while (time_before(jiffies, timeout)) {
> + regmap_read(rk_phy->reg_base,
> + rk_phy->phy_data->pcie_status,
> + &status);
> + if (status & PHY_PLL_LOCKED) {
> + dev_dbg(&phy->dev, "pll relocked!\n");
> + err = 0;
> + break;
> + }
> + msleep(20);
> + }
> +
> + if (err) {
> + dev_err(&phy->dev, "pll relock timeout!\n");
> + goto err_pll_lock;
> + }
> +
> + return 0;
> +
> +err_pll_lock:
> + reset_control_assert(rk_phy->phy_rst);
> + return err;
> +}
> +
> +static int rockchip_pcie_phy_init(struct phy *phy)
> +{
> + struct rockchip_pcie_phy *rk_phy = phy_get_drvdata(phy);
> + int err = 0;
> +
> + err = clk_prepare_enable(rk_phy->clk_pciephy_ref);
> + if (err) {
> + dev_err(&phy->dev, "Fail to enable pcie ref clock.\n");
> + goto err_refclk;
> + }
> +
> + err = reset_control_assert(rk_phy->phy_rst);
> + if (err) {
> + dev_err(&phy->dev, "assert phy_rst err %d\n", err);
> + goto err_reset;
> + }
> +
> + return err;
> +
> +err_reset:
> + clk_disable_unprepare(rk_phy->clk_pciephy_ref);
> +err_refclk:
> + return err;
> +}
> +
> +static int rockchip_pcie_phy_exit(struct phy *phy)
> +{
> + struct rockchip_pcie_phy *rk_phy = phy_get_drvdata(phy);
> + int err = 0;
> +
> + clk_disable_unprepare(rk_phy->clk_pciephy_ref);
> +
> + err = reset_control_deassert(rk_phy->phy_rst);
> + if (err) {
> + dev_err(&phy->dev, "deassert phy_rst err %d\n", err);
> + goto err_reset;
> + }
> +
> + return err;
> +
> +err_reset:
> + clk_prepare_enable(rk_phy->clk_pciephy_ref);
> + return err;
> +}
> +
> +static const struct phy_ops ops = {
> + .init = rockchip_pcie_phy_init,
> + .exit = rockchip_pcie_phy_exit,
> + .power_on = rockchip_pcie_phy_power_on,
> + .power_off = rockchip_pcie_phy_power_off,
> + .owner = THIS_MODULE,
> +};
> +
> +static const struct rockchip_pcie_data rk3399_pcie_data = {
> + .pcie_conf = 0xe220,
> + .pcie_status = 0xe2a4,
> + .pcie_laneoff = 0xe214,
> +};
> +
> +static const struct of_device_id rockchip_pcie_phy_dt_ids[] = {
> + {
> + .compatible = "rockchip,rk3399-pcie-phy",
> + .data = &rk3399_pcie_data,
> + },
> + {}
> +};
> +
> +MODULE_DEVICE_TABLE(of, rockchip_pcie_phy_dt_ids);
> +
> +static int rockchip_pcie_phy_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct rockchip_pcie_phy *rk_phy;
> + struct phy *generic_phy;
> + struct phy_provider *phy_provider;
> + struct regmap *grf;
> + const struct of_device_id *of_id;
> +
> + grf = syscon_node_to_regmap(dev->parent->of_node);
> + if (IS_ERR(grf)) {
> + dev_err(dev, "Cannot find GRF syscon\n");
> + return PTR_ERR(grf);
> + }
> +
> + rk_phy = devm_kzalloc(dev, sizeof(*rk_phy), GFP_KERNEL);
> + if (!rk_phy)
> + return -ENOMEM;
> +
> + of_id = of_match_device(rockchip_pcie_phy_dt_ids, &pdev->dev);
> + if (!of_id)
> + return -EINVAL;
> +
> + rk_phy->phy_data = (struct rockchip_pcie_data *)of_id->data;
> + rk_phy->reg_base = grf;
> +
> + rk_phy->phy_rst = devm_reset_control_get(dev, "phy");
> + if (IS_ERR(rk_phy->phy_rst)) {
> + if (PTR_ERR(rk_phy->phy_rst) != -EPROBE_DEFER)
> + dev_err(dev,
> + "missing phy property for reset controller\n");
> + return PTR_ERR(rk_phy->phy_rst);
> + }
> +
> + rk_phy->clk_pciephy_ref = devm_clk_get(dev, "refclk");
> + if (IS_ERR(rk_phy->clk_pciephy_ref)) {
> + dev_err(dev, "refclk not found.\n");
> + return PTR_ERR(rk_phy->clk_pciephy_ref);
> + }
> +
> + 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, rk_phy);
> + phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
> +
> + return PTR_ERR_OR_ZERO(phy_provider);
> +}
> +
> +static struct platform_driver rockchip_pcie_driver = {
> + .probe = rockchip_pcie_phy_probe,
> + .driver = {
> + .name = "rockchip-pcie-phy",
> + .of_match_table = rockchip_pcie_phy_dt_ids,
> + },
> +};
> +
> +module_platform_driver(rockchip_pcie_driver);
> +
> +MODULE_AUTHOR("Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("Rockchip PCIe PHY driver");
> +MODULE_LICENSE("GPL v2");
>