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

Liu Ying
2022-06-20T12:39:10Z

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
+#define MAX_CLKIN_FREQ 165000000
+
+#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);
+
+ 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",
+ 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);
+ }
+ 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);
+ 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);
+ 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");