diff options
Diffstat (limited to 'drivers/phy/phy-stih407-usb.c')
| -rw-r--r-- | drivers/phy/phy-stih407-usb.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/drivers/phy/phy-stih407-usb.c b/drivers/phy/phy-stih407-usb.c new file mode 100644 index 000000000000..42428d4181ea --- /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"); |