[PATCH v2 1/3] phy: amlogic: Add Amlogic AXG MIPI/PCIE PHY Driver

Remi Pommarel
2019-12-23T21:38:10Z

This adds support for the MIPI PHY also needed for PCIE found in the
Amlogic AXG SoC Family.

MIPI or PCIE selection is done by the #phy-cells, making the mode
static and exclusive.

For now only PCIE fonctionality is supported.

This PHY will be used to replace the mipi_enable clock gating logic
which was mistakenly added in the clock subsystem. This also activate
a non documented band gap bit in those registers that allows reliable
PCIE clock signal generation on AXG platforms.

Signed-off-by: Remi Pommarel <repk@triplefau.lt>
---
drivers/phy/amlogic/Kconfig | 11 ++
drivers/phy/amlogic/Makefile | 1 +
drivers/phy/amlogic/phy-meson-axg-mipi-pcie.c | 176 ++++++++++++++++++
3 files changed, 188 insertions(+)
create mode 100644 drivers/phy/amlogic/phy-meson-axg-mipi-pcie.c

diff --git a/drivers/phy/amlogic/Kconfig b/drivers/phy/amlogic/Kconfig
index af774ac2b934..1eeb75d018e3 100644
--- a/drivers/phy/amlogic/Kconfig
+++ b/drivers/phy/amlogic/Kconfig
@@ -59,3 +59,14 @@ config PHY_MESON_G12A_USB3_PCIE
Enable this to support the Meson USB3 + PCIE Combo PHY found
in Meson G12A SoCs.
If unsure, say N.
+
+config PHY_MESON_AXG_MIPI_PCIE
+ tristate "Meson AXG MIPI + PCIE PHY driver"
+ default ARCH_MESON
+ depends on OF && (ARCH_MESON || COMPILE_TEST)
+ select GENERIC_PHY
+ select MFD_SYSCON
+ help
+ Enable this to support the Meson MIPI + PCIE PHY found
+ in Meson AXG SoCs.
+ If unsure, say N.
diff --git a/drivers/phy/amlogic/Makefile b/drivers/phy/amlogic/Makefile
index 11d1c42ac2be..2167330a0ae8 100644
--- a/drivers/phy/amlogic/Makefile
+++ b/drivers/phy/amlogic/Makefile
@@ -4,3 +4,4 @@ obj-$(CONFIG_PHY_MESON_GXL_USB2) += phy-meson-gxl-usb2.o
obj-$(CONFIG_PHY_MESON_G12A_USB2) += phy-meson-g12a-usb2.o
obj-$(CONFIG_PHY_MESON_GXL_USB3) += phy-meson-gxl-usb3.o
obj-$(CONFIG_PHY_MESON_G12A_USB3_PCIE) += phy-meson-g12a-usb3-pcie.o
+obj-$(CONFIG_PHY_MESON_AXG_MIPI_PCIE) += phy-meson-axg-mipi-pcie.o
diff --git a/drivers/phy/amlogic/phy-meson-axg-mipi-pcie.c b/drivers/phy/amlogic/phy-meson-axg-mipi-pcie.c
new file mode 100644
index 000000000000..006aa8cdfc47
--- /dev/null
+++ b/drivers/phy/amlogic/phy-meson-axg-mipi-pcie.c
@@ -0,0 +1,176 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Amlogic AXG MIPI + PCIE PHY driver
+ *
+ * Copyright (C) 2019 Remi Pommarel <repk@triplefau.lt>
+ */
+#include <linux/module.h>
+#include <linux/phy/phy.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+#include <linux/platform_device.h>
+#include <dt-bindings/phy/phy.h>
+
+#define HHI_MIPI_CNTL0 0x00
+#define HHI_MIPI_CNTL0_COMMON_BLOCK GENMASK(31, 28)
+#define HHI_MIPI_CNTL0_ENABLE BIT(29)
+#define HHI_MIPI_CNTL0_BANDGAP BIT(26)
+#define HHI_MIPI_CNTL0_DECODE_TO_RTERM GENMASK(15, 12)
+#define HHI_MIPI_CNTL0_OUTPUT_EN BIT(3)
+
+#define HHI_MIPI_CNTL1 0x01
+#define HHI_MIPI_CNTL1_CH0_CML_PDR_EN BIT(12)
+#define HHI_MIPI_CNTL1_LP_ABILITY GENMASK(5, 4)
+#define HHI_MIPI_CNTL1_LP_RESISTER BIT(3)
+#define HHI_MIPI_CNTL1_INPUT_SETTING BIT(2)
+#define HHI_MIPI_CNTL1_INPUT_SEL BIT(1)
+#define HHI_MIPI_CNTL1_PRBS7_EN BIT(0)
+
+#define HHI_MIPI_CNTL2 0x02
+#define HHI_MIPI_CNTL2_CH_PU GENMASK(31, 25)
+#define HHI_MIPI_CNTL2_CH_CTL GENMASK(24, 19)
+#define HHI_MIPI_CNTL2_CH0_DIGDR_EN BIT(18)
+#define HHI_MIPI_CNTL2_CH_DIGDR_EN BIT(17)
+#define HHI_MIPI_CNTL2_LPULPS_EN BIT(16)
+#define HHI_MIPI_CNTL2_CH_EN(n) BIT(15 - (n))
+#define HHI_MIPI_CNTL2_CH0_LP_CTL GENMASK(10, 1)
+
+struct phy_axg_mipi_pcie_priv {
+ struct phy *phy;
+ unsigned int mode;
+ struct regmap *regmap;
+};
+
+static const struct regmap_config phy_axg_mipi_pcie_regmap_conf = {
+ .reg_bits = 8,
+ .val_bits = 32,
+ .reg_stride = 4,
+ .max_register = HHI_MIPI_CNTL2,
+};
+
+static int phy_axg_mipi_pcie_power_on(struct phy *phy)
+{
+ struct phy_axg_mipi_pcie_priv *priv = phy_get_drvdata(phy);
+
+ /* MIPI not supported yet */
+ if (priv->mode != PHY_TYPE_PCIE)
+ return 0;
+
+ regmap_update_bits(priv->regmap, HHI_MIPI_CNTL0,
+ HHI_MIPI_CNTL0_BANDGAP, HHI_MIPI_CNTL0_BANDGAP);
+
+ regmap_update_bits(priv->regmap, HHI_MIPI_CNTL0,
+ HHI_MIPI_CNTL0_ENABLE, HHI_MIPI_CNTL0_ENABLE);
+ return 0;
+}
+
+static int phy_axg_mipi_pcie_power_off(struct phy *phy)
+{
+ struct phy_axg_mipi_pcie_priv *priv = phy_get_drvdata(phy);
+
+ /* MIPI not supported yet */
+ if (priv->mode != PHY_TYPE_PCIE)
+ return 0;
+
+ regmap_update_bits(priv->regmap, HHI_MIPI_CNTL0,
+ HHI_MIPI_CNTL0_BANDGAP, 0);
+ regmap_update_bits(priv->regmap, HHI_MIPI_CNTL0,
+ HHI_MIPI_CNTL0_ENABLE, 0);
+ return 0;
+}
+
+static int phy_axg_mipi_pcie_init(struct phy *phy)
+{
+ return 0;
+}
+
+static int phy_axg_mipi_pcie_exit(struct phy *phy)
+{
+ return 0;
+}
+
+static const struct phy_ops phy_axg_mipi_pcie_ops = {
+ .init = phy_axg_mipi_pcie_init,
+ .exit = phy_axg_mipi_pcie_exit,
+ .power_on = phy_axg_mipi_pcie_power_on,
+ .power_off = phy_axg_mipi_pcie_power_off,
+ .owner = THIS_MODULE,
+};
+
+static struct phy *phy_axg_mipi_pcie_xlate(struct device *dev,
+ struct of_phandle_args *args)
+{
+ struct phy_axg_mipi_pcie_priv *priv = dev_get_drvdata(dev);
+ unsigned int mode;
+
+ if (args->args_count != 1) {
+ dev_err(dev, "invalid number of arguments\n");
+ return ERR_PTR(-EINVAL);
+ }
+
+ mode = args->args[0];
+
+ /* MIPI mode is not supported yet */
+ if (mode != PHY_TYPE_PCIE) {
+ dev_err(dev, "invalid phy mode select argument\n");
+ return ERR_PTR(-EINVAL);
+ }
+
+ priv->mode = mode;
+ return priv->phy;
+}
+
+static int phy_axg_mipi_pcie_probe(struct platform_device *pdev)
+{
+ struct phy_provider *pphy;
+ struct device *dev = &pdev->dev;
+ struct phy_axg_mipi_pcie_priv *priv;
+ struct device_node *np = dev->of_node;
+ int ret;
+
+ priv = devm_kmalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ /* Get the hhi system controller node */
+ priv->regmap = syscon_node_to_regmap(of_get_parent(dev->of_node));
+ if (IS_ERR(priv->regmap)) {
+ dev_err(dev, "failed to get HHI regmap\n");
+ return PTR_ERR(priv->regmap);
+ }
+
+ priv->phy = devm_phy_create(dev, np, &phy_axg_mipi_pcie_ops);
+ if (IS_ERR(priv->phy)) {
+ ret = PTR_ERR(priv->phy);
+ if (ret != -EPROBE_DEFER)
+ dev_err(dev, "failed to create PHY\n");
+ return ret;
+ }
+
+ phy_set_drvdata(priv->phy, priv);
+ dev_set_drvdata(dev, priv);
+ pphy = devm_of_phy_provider_register(dev, phy_axg_mipi_pcie_xlate);
+
+ return PTR_ERR_OR_ZERO(pphy);
+}
+
+static const struct of_device_id phy_axg_mipi_pcie_of_match[] = {
+ {
+ .compatible = "amlogic,axg-mipi-pcie-phy",
+ },
+ { },
+};
+MODULE_DEVICE_TABLE(of, phy_axg_mipi_pcie_of_match);
+
+static struct platform_driver phy_axg_mipi_pcie_driver = {
+ .probe = phy_axg_mipi_pcie_probe,
+ .driver = {
+ .name = "phy-axg-mipi-pcie",
+ .of_match_table = phy_axg_mipi_pcie_of_match,
+ },
+};
+module_platform_driver(phy_axg_mipi_pcie_driver);
+
+MODULE_AUTHOR("Remi Pommarel <repk@triplefau.lt>");
+MODULE_DESCRIPTION("Amlogic AXG MIPI + PCIE PHY driver");
+MODULE_LICENSE("GPL v2");
--
2.24.0