Message-ID: <57C96E7A.3070708@ti.com>
Date:   Fri, 2 Sep 2016 17:50:10 +0530
From:   Kishon Vijay Abraham I <kishon@...com>
To:     Shawn Lin <shawn.lin@...k-chips.com>
CC:     <linux-kernel@...r.kernel.org>,
        <linux-rockchip@...ts.infradead.org>,
        Heiko Stuebner <heiko@...ech.de>,
        Doug Anderson <dianders@...omium.org>,
        Brian Norris <briannorris@...omium.org>,
        Wenrui Li <wenrui.li@...k-chips.com>,
        Rob Herring <robh+dt@...nel.org>, <devicetree@...r.kernel.org>
Subject: Re: [PATCH v6 2/2] phy: add a driver for the Rockchip SoC internal
 PCIe PHY



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@...k-chips.com>

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@...k-chips.com>
> + * 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@...k-chips.com>");
> +MODULE_DESCRIPTION("Rockchip PCIe PHY driver");
> +MODULE_LICENSE("GPL v2");
> 

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