phy: phy-stih407-usb: Add usb picoPHY driver found on stih407 SoC family

This is the generic phy driver for the picoPHY ports used by the
USB2 and USB3 Host controllers when controlling usb2/1.1 devices. It
is found on STiH407 SoC family from STMicroelectronics.

Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index 1802fa767aa59681dcf84875ed9dab7ab9bd3fda..11c66d7ae252bce56a860b96cece6e23fae63359 100644 (file)
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -239,4 +239,13 @@ config PHY_XGENE
        help
          This option enables support for APM X-Gene SoC multi-purpose PHY.
 
+config PHY_STIH407_USB
+       tristate "STMicroelectronics USB2 picoPHY driver for STiH407 family"
+       depends on RESET_CONTROLLER
+       depends on ARCH_STI || COMPILE_TEST
+       select GENERIC_PHY
+       help
+         Enable this support to enable the picoPHY device used by USB2
+         and USB3 controllers on STMicroelectronics STiH407 SoC families.
+
 endmenu

diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index 8ac9df5bd06910ada5c45fb63cf7d560152d13e5..a8d1e114a8afd9f5f8de56c181bcb80f3a043d52 100644 (file)
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -29,3 +29,4 @@ obj-$(CONFIG_PHY_QCOM_IPQ806X_SATA)   += phy-qcom-ipq806x-sata.o
 obj-$(CONFIG_PHY_ST_SPEAR1310_MIPHY)   += phy-spear1310-miphy.o
 obj-$(CONFIG_PHY_ST_SPEAR1340_MIPHY)   += phy-spear1340-miphy.o
 obj-$(CONFIG_PHY_XGENE)                        += phy-xgene.o
+obj-$(CONFIG_PHY_STIH407_USB)          += phy-stih407-usb.o

diff --git a/drivers/phy/phy-stih407-usb.c b/drivers/phy/phy-stih407-usb.c
new file mode 100644 (file)
index 0000000..42428d4
--- /dev/null
+++ b/drivers/phy/phy-stih407-usb.c
@@ -0,0 +1,177 @@
+/*
+ * Copyright (C) 2014 STMicroelectronics
+ *
+ * STMicroelectronics Generic PHY driver for STiH407 USB2.
+ *
+ * Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2, as
+ * published by the Free Software Foundation.
+ *
+ */
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/clk.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+#include <linux/mfd/syscon.h>
+#include <linux/phy/phy.h>
+
+/* Default PHY_SEL and REFCLKSEL configuration */
+#define STIH407_USB_PICOPHY_CTRL_PORT_CONF     0x6
+#define STIH407_USB_PICOPHY_CTRL_PORT_MASK     0x1f
+
+/* ports parameters overriding */
+#define STIH407_USB_PICOPHY_PARAM_DEF          0x39a4dc
+#define STIH407_USB_PICOPHY_PARAM_MASK         0xffffffff
+
+struct stih407_usb2_picophy {
+       struct phy *phy;
+       struct regmap *regmap;
+       struct device *dev;
+       struct reset_control *rstc;
+       struct reset_control *rstport;
+       int ctrl;
+       int param;
+};
+
+static int stih407_usb2_pico_ctrl(struct stih407_usb2_picophy *phy_dev)
+{
+       reset_control_deassert(phy_dev->rstc);
+
+       return regmap_update_bits(phy_dev->regmap, phy_dev->ctrl,
+                                 STIH407_USB_PICOPHY_CTRL_PORT_MASK,
+                                 STIH407_USB_PICOPHY_CTRL_PORT_CONF);
+}
+
+static int stih407_usb2_init_port(struct phy *phy)
+{
+       int ret;
+       struct stih407_usb2_picophy *phy_dev = phy_get_drvdata(phy);
+
+       stih407_usb2_pico_ctrl(phy_dev);
+
+       ret = regmap_update_bits(phy_dev->regmap,
+                                phy_dev->param,
+                                STIH407_USB_PICOPHY_PARAM_MASK,
+                                STIH407_USB_PICOPHY_PARAM_DEF);
+       if (ret)
+               return ret;
+
+       return reset_control_deassert(phy_dev->rstport);
+}
+
+static int stih407_usb2_exit_port(struct phy *phy)
+{
+       struct stih407_usb2_picophy *phy_dev = phy_get_drvdata(phy);
+
+       /*
+        * Only port reset is asserted, phy global reset is kept untouched
+        * as other ports may still be active. When all ports are in reset
+        * state, assumption is made that power will be cut off on the phy, in
+        * case of suspend for instance. Theoretically, asserting individual
+        * reset (like here) or global reset should be equivalent.
+        */
+       return reset_control_assert(phy_dev->rstport);
+}
+
+static const struct phy_ops stih407_usb2_picophy_data = {
+       .init = stih407_usb2_init_port,
+       .exit = stih407_usb2_exit_port,
+       .owner = THIS_MODULE,
+};
+
+static int stih407_usb2_picophy_probe(struct platform_device *pdev)
+{
+       struct stih407_usb2_picophy *phy_dev;
+       struct device *dev = &pdev->dev;
+       struct device_node *np = dev->of_node;
+       struct phy_provider *phy_provider;
+       struct phy *phy;
+       struct resource *res;
+
+       phy_dev = devm_kzalloc(dev, sizeof(*phy_dev), GFP_KERNEL);
+       if (!phy_dev)
+               return -ENOMEM;
+
+       phy_dev->dev = dev;
+       dev_set_drvdata(dev, phy_dev);
+
+       phy_dev->rstc = devm_reset_control_get(dev, "global");
+       if (IS_ERR(phy_dev->rstc)) {
+               dev_err(dev, "failed to ctrl picoPHY reset\n");
+               return PTR_ERR(phy_dev->rstc);
+       }
+
+       phy_dev->rstport = devm_reset_control_get(dev, "port");
+       if (IS_ERR(phy_dev->rstport)) {
+               dev_err(dev, "failed to ctrl picoPHY reset\n");
+               return PTR_ERR(phy_dev->rstport);
+       }
+
+       /* Reset port by default: only deassert it in phy init */
+       reset_control_assert(phy_dev->rstport);
+
+       phy_dev->regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
+       if (IS_ERR(phy_dev->regmap)) {
+               dev_err(dev, "No syscfg phandle specified\n");
+               return PTR_ERR(phy_dev->regmap);
+       }
+
+       res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ctrl");
+       if (!res) {
+               dev_err(dev, "No ctrl reg found\n");
+               return -ENXIO;
+       }
+       phy_dev->ctrl = res->start;
+
+       res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "param");
+       if (!res) {
+               dev_err(dev, "No param reg found\n");
+               return -ENXIO;
+       }
+       phy_dev->param = res->start;
+
+       phy = devm_phy_create(dev, NULL, &stih407_usb2_picophy_data, NULL);
+       if (IS_ERR(phy)) {
+               dev_err(dev, "failed to create Display Port PHY\n");
+               return PTR_ERR(phy);
+       }
+
+       phy_dev->phy = phy;
+       phy_set_drvdata(phy, phy_dev);
+
+       phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+       if (IS_ERR(phy_provider))
+               return PTR_ERR(phy_provider);
+
+       dev_info(dev, "STiH407 USB Generic picoPHY driver probed!");
+
+       return 0;
+}
+
+static const struct of_device_id stih407_usb2_picophy_of_match[] = {
+       { .compatible = "st,stih407-usb2-phy" },
+       { /*sentinel */ },
+};
+
+MODULE_DEVICE_TABLE(of, stih407_usb2_picophy_of_match);
+
+static struct platform_driver stih407_usb2_picophy_driver = {
+       .probe = stih407_usb2_picophy_probe,
+       .driver = {
+                  .name = "stih407-usb-genphy",
+                  .of_match_table = stih407_usb2_picophy_of_match,
+                  }
+};
+
+module_platform_driver(stih407_usb2_picophy_driver);
+
+MODULE_AUTHOR("Giuseppe Cavallaro <peppe.cavallaro@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics Generic picoPHY driver for STiH407");
+MODULE_LICENSE("GPL v2");