Re: [PATCH v3 3/3] phy: freescale: Add i.MX8qm Mixel LVDS PHY support

Vinod Koul
2022-07-05T09:04:39Z

On 20-06-22, 20:38, Liu Ying wrote:
> Add Freescale i.MX8qm LVDS PHY support.
> The PHY IP is from Mixel, Inc.
>
> Signed-off-by: Liu Ying <victor.liu@nxp.com>
> ---
> v2->v3:
> * No change.
>
> v1->v2:
> * Drop 'This patch' from commit message. (Krzysztof)
> * Make dev_err_probe() function calls as one-liners. (Krzysztof)
> * Drop unnecessary debug messages. (Krzysztof)
> * Get phy_ref_clk without name specified due to 'clock-names' dropped from
> dt-binding.
>
> drivers/phy/freescale/Kconfig | 9 +
> drivers/phy/freescale/Makefile | 1 +
> .../phy/freescale/phy-fsl-imx8qm-lvds-phy.c | 440 ++++++++++++++++++
> 3 files changed, 450 insertions(+)
> create mode 100644 drivers/phy/freescale/phy-fsl-imx8qm-lvds-phy.c
>
> diff --git a/drivers/phy/freescale/Kconfig b/drivers/phy/freescale/Kconfig
> index f9c54cd02036..853958fb2c06 100644
> --- a/drivers/phy/freescale/Kconfig
> +++ b/drivers/phy/freescale/Kconfig
> @@ -8,6 +8,15 @@ config PHY_FSL_IMX8MQ_USB
> select GENERIC_PHY
> default ARCH_MXC && ARM64
>
> +config PHY_MIXEL_LVDS_PHY
> + tristate "Mixel LVDS PHY support"
> + depends on OF
> + select GENERIC_PHY
> + select REGMAP_MMIO
> + help
> + Enable this to add support for the Mixel LVDS PHY as found
> + on NXP's i.MX8qm SoC.
> +
> config PHY_MIXEL_MIPI_DPHY
> tristate "Mixel MIPI DSI PHY support"
> depends on OF && HAS_IOMEM
> diff --git a/drivers/phy/freescale/Makefile b/drivers/phy/freescale/Makefile
> index 3518d5dbe8a7..cedb328bc4d2 100644
> --- a/drivers/phy/freescale/Makefile
> +++ b/drivers/phy/freescale/Makefile
> @@ -1,5 +1,6 @@
> # SPDX-License-Identifier: GPL-2.0-only
> obj-$(CONFIG_PHY_FSL_IMX8MQ_USB) += phy-fsl-imx8mq-usb.o
> +obj-$(CONFIG_PHY_MIXEL_LVDS_PHY) += phy-fsl-imx8qm-lvds-phy.o
> obj-$(CONFIG_PHY_MIXEL_MIPI_DPHY) += phy-fsl-imx8-mipi-dphy.o
> obj-$(CONFIG_PHY_FSL_IMX8M_PCIE) += phy-fsl-imx8m-pcie.o
> obj-$(CONFIG_PHY_FSL_LYNX_28G) += phy-fsl-lynx-28g.o
> diff --git a/drivers/phy/freescale/phy-fsl-imx8qm-lvds-phy.c b/drivers/phy/freescale/phy-fsl-imx8qm-lvds-phy.c
> new file mode 100644
> index 000000000000..37f77115ddab
> --- /dev/null
> +++ b/drivers/phy/freescale/phy-fsl-imx8qm-lvds-phy.c
> @@ -0,0 +1,440 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright 2017-2020,2022 NXP
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/bits.h>
> +#include <linux/clk.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/phy/phy.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/regmap.h>
> +
> +#define REG_SET 0x4
> +#define REG_CLR 0x8
> +
> +#define PHY_CTRL 0x0
> +#define M_MASK GENMASK(18, 17)
> +#define M(n) FIELD_PREP(M_MASK, (n))
> +#define CCM_MASK GENMASK(16, 14)
> +#define CCM(n) FIELD_PREP(CCM_MASK, (n))
> +#define CA_MASK GENMASK(13, 11)
> +#define CA(n) FIELD_PREP(CA_MASK, (n))
> +#define TST_MASK GENMASK(10, 5)
> +#define TST(n) FIELD_PREP(TST_MASK, (n))
> +#define CH_EN(id) BIT(3 + (id))
> +#define NB BIT(2)
> +#define RFB BIT(1)
> +#define PD BIT(0)
> +
> +/* Power On Reset(POR) value */
> +#define CTRL_RESET_VAL (M(0x0) | CCM(0x4) | CA(0x4) | TST(0x25))
> +
> +/* PHY initialization value and mask */
> +#define CTRL_INIT_MASK (M_MASK | CCM_MASK | CA_MASK | TST_MASK | NB | RFB)
> +#define CTRL_INIT_VAL (M(0x0) | CCM(0x5) | CA(0x4) | TST(0x25) | RFB)
> +
> +#define PHY_STATUS 0x10
> +#define LOCK BIT(0)
> +
> +#define PHY_NUM 2
> +
> +#define MIN_CLKIN_FREQ 25000000

this is 25MHz, so lets write as 25 * MEGA (see units.h)

> +#define MAX_CLKIN_FREQ 165000000

here too

> +
> +#define PLL_LOCK_SLEEP 10
> +#define PLL_LOCK_TIMEOUT 1000
> +
> +struct mixel_lvds_phy {
> + struct phy *phy;
> + struct phy_configure_opts_lvds cfg;
> + unsigned int id;
> +};
> +
> +struct mixel_lvds_phy_priv {
> + struct regmap *regmap;
> + struct mutex lock; /* protect remap access and cfg of our own */
> + struct clk *phy_ref_clk;
> + struct mixel_lvds_phy *phys[PHY_NUM];
> +};
> +
> +static int mixel_lvds_phy_init(struct phy *phy)
> +{
> + struct mixel_lvds_phy_priv *priv = dev_get_drvdata(phy->dev.parent);
> +
> + mutex_lock(&priv->lock);
> + regmap_update_bits(priv->regmap,
> + PHY_CTRL, CTRL_INIT_MASK, CTRL_INIT_VAL);
> + mutex_unlock(&priv->lock);
> +
> + return 0;
> +}
> +
> +static int mixel_lvds_phy_power_on(struct phy *phy)
> +{
> + struct mixel_lvds_phy_priv *priv = dev_get_drvdata(phy->dev.parent);
> + struct mixel_lvds_phy *lvds_phy = phy_get_drvdata(phy);
> + struct mixel_lvds_phy *companion = priv->phys[lvds_phy->id ^ 1];
> + struct phy_configure_opts_lvds *cfg = &lvds_phy->cfg;
> + u32 val = 0;
> + u32 locked;
> + int ret;
> +
> + ret = clk_prepare_enable(priv->phy_ref_clk);
> + if (ret < 0) {
> + dev_err(&phy->dev,
> + "failed to enable PHY reference clock: %d\n", ret);
> + return ret;
> + }
> +
> + /* The master PHY would power on the slave PHY. */
> + if (cfg->is_slave)
> + return 0;
> +
> + mutex_lock(&priv->lock);
> + if (cfg->bits_per_lane_and_dclk_cycle == 7) {
> + if (cfg->differential_clk_rate < 44000000)
> + val |= M(0x2);
> + else if (cfg->differential_clk_rate < 90000000)
> + val |= M(0x1);
> + else
> + val |= M(0x0);
> + } else {
> + val = NB;
> +
> + if (cfg->differential_clk_rate < 32000000)
> + val |= M(0x2);
> + else if (cfg->differential_clk_rate < 63000000)
> + val |= M(0x1);
> + else
> + val |= M(0x0);
> + }
> + regmap_update_bits(priv->regmap, PHY_CTRL, M_MASK | NB, val);
> +
> + /*
> + * Enable two channels synchronously,
> + * if the companion PHY is a slave PHY.
> + */
> + if (companion->cfg.is_slave)
> + val = CH_EN(0) | CH_EN(1);
> + else
> + val = CH_EN(lvds_phy->id);
> + regmap_write(priv->regmap, PHY_CTRL + REG_SET, val);
> +
> + ret = regmap_read_poll_timeout(priv->regmap, PHY_STATUS, locked,
> + locked, PLL_LOCK_SLEEP,
> + PLL_LOCK_TIMEOUT);
> + if (ret < 0) {
> + dev_err(&phy->dev, "failed to get PHY lock: %d\n", ret);
> + clk_disable_unprepare(priv->phy_ref_clk);
> + }
> + mutex_unlock(&priv->lock);
> +
> + return ret;
> +}
> +
> +static int mixel_lvds_phy_power_off(struct phy *phy)
> +{
> + struct mixel_lvds_phy_priv *priv = dev_get_drvdata(phy->dev.parent);
> + struct mixel_lvds_phy *lvds_phy = phy_get_drvdata(phy);
> +
> + mutex_lock(&priv->lock);
> + regmap_write(priv->regmap, PHY_CTRL + REG_CLR, CH_EN(lvds_phy->id));
> + mutex_unlock(&priv->lock);

No check for slave here?

> +
> + clk_disable_unprepare(priv->phy_ref_clk);
> +
> + return 0;
> +}
> +
> +static int mixel_lvds_phy_configure(struct phy *phy,
> + union phy_configure_opts *opts)
> +{
> + struct mixel_lvds_phy_priv *priv = dev_get_drvdata(phy->dev.parent);
> + struct phy_configure_opts_lvds *cfg = &opts->lvds;
> + int ret;
> +
> + ret = clk_set_rate(priv->phy_ref_clk, cfg->differential_clk_rate);
> + if (ret)
> + dev_err(&phy->dev,
> + "failed to set PHY reference clock rate(%lu): %d\n",

this can fit in a single line (100 chars is okay)

> + cfg->differential_clk_rate, ret);
> +
> + return ret;
> +}
> +
> +/* Assume the master PHY's configuration set is cached first. */
> +static int mixel_lvds_phy_check_slave(struct phy *slave_phy)
> +{
> + struct device *dev = &slave_phy->dev;
> + struct mixel_lvds_phy_priv *priv = dev_get_drvdata(dev->parent);
> + struct mixel_lvds_phy *slv = phy_get_drvdata(slave_phy);
> + struct mixel_lvds_phy *mst = priv->phys[slv->id ^ 1];
> + struct phy_configure_opts_lvds *mst_cfg = &mst->cfg;
> + struct phy_configure_opts_lvds *slv_cfg = &slv->cfg;
> +
> + if (mst_cfg->bits_per_lane_and_dclk_cycle !=
> + slv_cfg->bits_per_lane_and_dclk_cycle) {
> + dev_err(dev, "number bits mismatch(mst: %u vs slv: %u)\n",
> + mst_cfg->bits_per_lane_and_dclk_cycle,
> + slv_cfg->bits_per_lane_and_dclk_cycle);
> + return -EINVAL;
> + }
> +
> + if (mst_cfg->differential_clk_rate !=
> + slv_cfg->differential_clk_rate) {
> + dev_err(dev, "dclk rate mismatch(mst: %lu vs slv: %lu)\n",
> + mst_cfg->differential_clk_rate,
> + slv_cfg->differential_clk_rate);
> + return -EINVAL;
> + }
> +
> + if (mst_cfg->lanes != slv_cfg->lanes) {
> + dev_err(dev, "lanes mismatch(mst: %u vs slv: %u)\n",
> + mst_cfg->lanes, slv_cfg->lanes);
> + return -EINVAL;
> + }
> +
> + if (mst_cfg->is_slave == slv_cfg->is_slave) {
> + dev_err(dev, "master PHY is not found\n");
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> +static int mixel_lvds_phy_validate(struct phy *phy, enum phy_mode mode,
> + int submode, union phy_configure_opts *opts)
> +{
> + struct mixel_lvds_phy_priv *priv = dev_get_drvdata(phy->dev.parent);
> + struct mixel_lvds_phy *lvds_phy = phy_get_drvdata(phy);
> + struct phy_configure_opts_lvds *cfg = &opts->lvds;
> + int ret = 0;
> +
> + if (mode != PHY_MODE_LVDS) {
> + dev_err(&phy->dev, "invalid PHY mode(%d)\n", mode);
> + return -EINVAL;
> + }
> +
> + if (cfg->bits_per_lane_and_dclk_cycle != 7 &&
> + cfg->bits_per_lane_and_dclk_cycle != 10) {
> + dev_err(&phy->dev, "invalid bits per data lane(%u)\n",
> + cfg->bits_per_lane_and_dclk_cycle);
> + return -EINVAL;
> + }
> +
> + if (cfg->lanes != 4 && cfg->lanes != 3) {
> + dev_err(&phy->dev, "invalid data lanes(%u)\n", cfg->lanes);
> + return -EINVAL;
> + }
> +
> + if (cfg->differential_clk_rate < MIN_CLKIN_FREQ ||
> + cfg->differential_clk_rate > MAX_CLKIN_FREQ) {
> + dev_err(&phy->dev, "invalid differential clock rate(%lu)\n",
> + cfg->differential_clk_rate);
> + return -EINVAL;
> + }
> +
> + mutex_lock(&priv->lock);
> + /* cache configuration set of our own for check */
> + memcpy(&lvds_phy->cfg, cfg, sizeof(*cfg));
> +
> + if (cfg->is_slave) {
> + ret = mixel_lvds_phy_check_slave(phy);
> + if (ret)
> + dev_err(&phy->dev,
> + "failed to check slave PHY: %d\n", ret);

very ugly, single line pls

> + }
> + mutex_unlock(&priv->lock);
> +
> + return ret;
> +}
> +
> +static const struct phy_ops mixel_lvds_phy_ops = {
> + .init = mixel_lvds_phy_init,
> + .power_on = mixel_lvds_phy_power_on,
> + .power_off = mixel_lvds_phy_power_off,
> + .configure = mixel_lvds_phy_configure,
> + .validate = mixel_lvds_phy_validate,
> + .owner = THIS_MODULE,
> +};
> +
> +static int mixel_lvds_phy_reset(struct device *dev)
> +{
> + struct mixel_lvds_phy_priv *priv = dev_get_drvdata(dev);
> + int ret;
> +
> + ret = pm_runtime_get_sync(dev);

pm_runtime_resume_and_get() pls

> + if (ret < 0) {
> + dev_err(dev, "failed to get PM runtime: %d\n", ret);
> + return ret;
> + }
> +
> + regmap_write(priv->regmap, PHY_CTRL, CTRL_RESET_VAL);
> +
> + ret = pm_runtime_put(dev);

this seems to be done only around reset, why not in on/off method?

> + if (ret < 0)
> + dev_err(dev, "failed to put PM runtime: %d\n", ret);
> +
> + return ret;
> +}
> +
> +static struct phy *mixel_lvds_phy_xlate(struct device *dev,
> + struct of_phandle_args *args)
> +{
> + struct mixel_lvds_phy_priv *priv = dev_get_drvdata(dev);
> + unsigned int phy_id;
> +
> + if (args->args_count != 1) {
> + dev_err(dev,
> + "invalid argument number(%d) for 'phys' property\n",
> + args->args_count);
> + return ERR_PTR(-EINVAL);
> + }
> +
> + phy_id = args->args[0];
> +
> + if (phy_id >= PHY_NUM) {
> + dev_err(dev, "invalid PHY index(%d)\n", phy_id);
> + return ERR_PTR(-ENODEV);
> + }
> +
> + return priv->phys[phy_id]->phy;
> +}
> +
> +static int mixel_lvds_phy_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct phy_provider *phy_provider;
> + struct mixel_lvds_phy_priv *priv;
> + struct mixel_lvds_phy *lvds_phy;
> + struct phy *phy;
> + int i;
> + int ret;
> +
> + if (!dev->of_node)
> + return -ENODEV;
> +
> + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + priv->regmap = syscon_node_to_regmap(dev->of_node->parent);
> + if (IS_ERR(priv->regmap))
> + return dev_err_probe(dev, PTR_ERR(priv->regmap),
> + "failed to get regmap\n");
> +
> + priv->phy_ref_clk = devm_clk_get(dev, NULL);
> + if (IS_ERR(priv->phy_ref_clk))
> + return dev_err_probe(dev, PTR_ERR(priv->phy_ref_clk),
> + "failed to get PHY reference clock\n");
> +
> + mutex_init(&priv->lock);
> +
> + dev_set_drvdata(dev, priv);
> +
> + pm_runtime_enable(dev);
> +
> + ret = mixel_lvds_phy_reset(dev);
> + if (ret) {
> + dev_err(dev, "failed to do POR reset: %d\n", ret);
> + return ret;
> + }
> +
> + for (i = 0; i < PHY_NUM; i++) {
> + lvds_phy = devm_kzalloc(dev, sizeof(*lvds_phy), GFP_KERNEL);
> + if (!lvds_phy) {
> + ret = -ENOMEM;
> + goto err;
> + }
> +
> + phy = devm_phy_create(dev, NULL, &mixel_lvds_phy_ops);
> + if (IS_ERR(phy)) {
> + ret = PTR_ERR(phy);
> + dev_err(dev, "failed to create PHY for channel%d: %d\n",
> + i, ret);
> + goto err;
> + }
> +
> + lvds_phy->phy = phy;
> + lvds_phy->id = i;
> + priv->phys[i] = lvds_phy;
> +
> + phy_set_drvdata(phy, lvds_phy);
> + }
> +
> + phy_provider = devm_of_phy_provider_register(dev, mixel_lvds_phy_xlate);
> + if (IS_ERR(phy_provider)) {
> + ret = PTR_ERR(phy_provider);
> + dev_err(dev, "failed to register PHY provider: %d\n", ret);
> + goto err;
> + }
> +
> + return 0;
> +err:
> + pm_runtime_disable(dev);
> +
> + return ret;
> +}
> +
> +static int mixel_lvds_phy_remove(struct platform_device *pdev)
> +{
> + pm_runtime_disable(&pdev->dev);
> +
> + return 0;
> +}
> +
> +static int __maybe_unused mixel_lvds_phy_runtime_suspend(struct device *dev)
> +{
> + struct mixel_lvds_phy_priv *priv = dev_get_drvdata(dev);
> +
> + /* power down */
> + mutex_lock(&priv->lock);
> + regmap_write(priv->regmap, PHY_CTRL + REG_SET, PD);
> + mutex_unlock(&priv->lock);
> +
> + return 0;
> +}
> +
> +static int __maybe_unused mixel_lvds_phy_runtime_resume(struct device *dev)
> +{
> + struct mixel_lvds_phy_priv *priv = dev_get_drvdata(dev);
> +
> + /* power up + control initialization */
> + mutex_lock(&priv->lock);
> + regmap_update_bits(priv->regmap, PHY_CTRL,
> + CTRL_INIT_MASK | PD, CTRL_INIT_VAL);
> + mutex_unlock(&priv->lock);
> +
> + return 0;
> +}
> +
> +static const struct dev_pm_ops mixel_lvds_phy_pm_ops = {
> + SET_RUNTIME_PM_OPS(mixel_lvds_phy_runtime_suspend,
> + mixel_lvds_phy_runtime_resume, NULL)
> +};
> +
> +static const struct of_device_id mixel_lvds_phy_of_match[] = {
> + { .compatible = "fsl,imx8qm-lvds-phy" },
> + { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, mixel_lvds_phy_of_match);
> +
> +static struct platform_driver mixel_lvds_phy_driver = {
> + .probe = mixel_lvds_phy_probe,
> + .remove = mixel_lvds_phy_remove,
> + .driver = {
> + .pm = &mixel_lvds_phy_pm_ops,
> + .name = "mixel-lvds-phy",
> + .of_match_table = mixel_lvds_phy_of_match,
> + }
> +};
> +module_platform_driver(mixel_lvds_phy_driver);
> +
> +MODULE_DESCRIPTION("Mixel LVDS PHY driver");
> +MODULE_AUTHOR("Liu Ying <victor.liu@nxp.com>");
> +MODULE_LICENSE("GPL");
> --
> 2.25.1

--
~Vinod