diff options
Diffstat (limited to 'drivers/phy/renesas/phy-rcar-gen2.c')
-rw-r--r-- | drivers/phy/renesas/phy-rcar-gen2.c | 339 |
1 files changed, 339 insertions, 0 deletions
diff --git a/drivers/phy/renesas/phy-rcar-gen2.c b/drivers/phy/renesas/phy-rcar-gen2.c new file mode 100644 index 000000000..aa02b19b7 --- /dev/null +++ b/drivers/phy/renesas/phy-rcar-gen2.c @@ -0,0 +1,339 @@ +/* + * Renesas R-Car Gen2 PHY driver + * + * Copyright (C) 2014 Renesas Solutions Corp. + * Copyright (C) 2014 Cogent Embedded, Inc. + * + * 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/clk.h> +#include <linux/delay.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/phy/phy.h> +#include <linux/platform_device.h> +#include <linux/spinlock.h> +#include <linux/atomic.h> + +#define USBHS_LPSTS 0x02 +#define USBHS_UGCTRL 0x80 +#define USBHS_UGCTRL2 0x84 +#define USBHS_UGSTS 0x88 /* From technical update */ + +/* Low Power Status register (LPSTS) */ +#define USBHS_LPSTS_SUSPM 0x4000 + +/* USB General control register (UGCTRL) */ +#define USBHS_UGCTRL_CONNECT 0x00000004 +#define USBHS_UGCTRL_PLLRESET 0x00000001 + +/* USB General control register 2 (UGCTRL2) */ +#define USBHS_UGCTRL2_USB2SEL 0x80000000 +#define USBHS_UGCTRL2_USB2SEL_PCI 0x00000000 +#define USBHS_UGCTRL2_USB2SEL_USB30 0x80000000 +#define USBHS_UGCTRL2_USB0SEL 0x00000030 +#define USBHS_UGCTRL2_USB0SEL_PCI 0x00000010 +#define USBHS_UGCTRL2_USB0SEL_HS_USB 0x00000030 + +/* USB General status register (UGSTS) */ +#define USBHS_UGSTS_LOCK 0x00000100 /* From technical update */ + +#define PHYS_PER_CHANNEL 2 + +struct rcar_gen2_phy { + struct phy *phy; + struct rcar_gen2_channel *channel; + int number; + u32 select_value; +}; + +struct rcar_gen2_channel { + struct device_node *of_node; + struct rcar_gen2_phy_driver *drv; + struct rcar_gen2_phy phys[PHYS_PER_CHANNEL]; + int selected_phy; + u32 select_mask; +}; + +struct rcar_gen2_phy_driver { + void __iomem *base; + struct clk *clk; + spinlock_t lock; + int num_channels; + struct rcar_gen2_channel *channels; +}; + +static int rcar_gen2_phy_init(struct phy *p) +{ + struct rcar_gen2_phy *phy = phy_get_drvdata(p); + struct rcar_gen2_channel *channel = phy->channel; + struct rcar_gen2_phy_driver *drv = channel->drv; + unsigned long flags; + u32 ugctrl2; + + /* + * Try to acquire exclusive access to PHY. The first driver calling + * phy_init() on a given channel wins, and all attempts to use another + * PHY on this channel will fail until phy_exit() is called by the first + * driver. Achieving this with cmpxcgh() should be SMP-safe. + */ + if (cmpxchg(&channel->selected_phy, -1, phy->number) != -1) + return -EBUSY; + + clk_prepare_enable(drv->clk); + + spin_lock_irqsave(&drv->lock, flags); + ugctrl2 = readl(drv->base + USBHS_UGCTRL2); + ugctrl2 &= ~channel->select_mask; + ugctrl2 |= phy->select_value; + writel(ugctrl2, drv->base + USBHS_UGCTRL2); + spin_unlock_irqrestore(&drv->lock, flags); + return 0; +} + +static int rcar_gen2_phy_exit(struct phy *p) +{ + struct rcar_gen2_phy *phy = phy_get_drvdata(p); + struct rcar_gen2_channel *channel = phy->channel; + + clk_disable_unprepare(channel->drv->clk); + + channel->selected_phy = -1; + + return 0; +} + +static int rcar_gen2_phy_power_on(struct phy *p) +{ + struct rcar_gen2_phy *phy = phy_get_drvdata(p); + struct rcar_gen2_phy_driver *drv = phy->channel->drv; + void __iomem *base = drv->base; + unsigned long flags; + u32 value; + int err = 0, i; + + /* Skip if it's not USBHS */ + if (phy->select_value != USBHS_UGCTRL2_USB0SEL_HS_USB) + return 0; + + spin_lock_irqsave(&drv->lock, flags); + + /* Power on USBHS PHY */ + value = readl(base + USBHS_UGCTRL); + value &= ~USBHS_UGCTRL_PLLRESET; + writel(value, base + USBHS_UGCTRL); + + value = readw(base + USBHS_LPSTS); + value |= USBHS_LPSTS_SUSPM; + writew(value, base + USBHS_LPSTS); + + for (i = 0; i < 20; i++) { + value = readl(base + USBHS_UGSTS); + if ((value & USBHS_UGSTS_LOCK) == USBHS_UGSTS_LOCK) { + value = readl(base + USBHS_UGCTRL); + value |= USBHS_UGCTRL_CONNECT; + writel(value, base + USBHS_UGCTRL); + goto out; + } + udelay(1); + } + + /* Timed out waiting for the PLL lock */ + err = -ETIMEDOUT; + +out: + spin_unlock_irqrestore(&drv->lock, flags); + + return err; +} + +static int rcar_gen2_phy_power_off(struct phy *p) +{ + struct rcar_gen2_phy *phy = phy_get_drvdata(p); + struct rcar_gen2_phy_driver *drv = phy->channel->drv; + void __iomem *base = drv->base; + unsigned long flags; + u32 value; + + /* Skip if it's not USBHS */ + if (phy->select_value != USBHS_UGCTRL2_USB0SEL_HS_USB) + return 0; + + spin_lock_irqsave(&drv->lock, flags); + + /* Power off USBHS PHY */ + value = readl(base + USBHS_UGCTRL); + value &= ~USBHS_UGCTRL_CONNECT; + writel(value, base + USBHS_UGCTRL); + + value = readw(base + USBHS_LPSTS); + value &= ~USBHS_LPSTS_SUSPM; + writew(value, base + USBHS_LPSTS); + + value = readl(base + USBHS_UGCTRL); + value |= USBHS_UGCTRL_PLLRESET; + writel(value, base + USBHS_UGCTRL); + + spin_unlock_irqrestore(&drv->lock, flags); + + return 0; +} + +static const struct phy_ops rcar_gen2_phy_ops = { + .init = rcar_gen2_phy_init, + .exit = rcar_gen2_phy_exit, + .power_on = rcar_gen2_phy_power_on, + .power_off = rcar_gen2_phy_power_off, + .owner = THIS_MODULE, +}; + +static const struct of_device_id rcar_gen2_phy_match_table[] = { + { .compatible = "renesas,usb-phy-r8a7790" }, + { .compatible = "renesas,usb-phy-r8a7791" }, + { .compatible = "renesas,usb-phy-r8a7794" }, + { .compatible = "renesas,rcar-gen2-usb-phy" }, + { } +}; +MODULE_DEVICE_TABLE(of, rcar_gen2_phy_match_table); + +static struct phy *rcar_gen2_phy_xlate(struct device *dev, + struct of_phandle_args *args) +{ + struct rcar_gen2_phy_driver *drv; + struct device_node *np = args->np; + int i; + + drv = dev_get_drvdata(dev); + if (!drv) + return ERR_PTR(-EINVAL); + + for (i = 0; i < drv->num_channels; i++) { + if (np == drv->channels[i].of_node) + break; + } + + if (i >= drv->num_channels || args->args[0] >= 2) + return ERR_PTR(-ENODEV); + + return drv->channels[i].phys[args->args[0]].phy; +} + +static const u32 select_mask[] = { + [0] = USBHS_UGCTRL2_USB0SEL, + [2] = USBHS_UGCTRL2_USB2SEL, +}; + +static const u32 select_value[][PHYS_PER_CHANNEL] = { + [0] = { USBHS_UGCTRL2_USB0SEL_PCI, USBHS_UGCTRL2_USB0SEL_HS_USB }, + [2] = { USBHS_UGCTRL2_USB2SEL_PCI, USBHS_UGCTRL2_USB2SEL_USB30 }, +}; + +static int rcar_gen2_phy_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct rcar_gen2_phy_driver *drv; + struct phy_provider *provider; + struct device_node *np; + struct resource *res; + void __iomem *base; + struct clk *clk; + int i = 0; + + if (!dev->of_node) { + dev_err(dev, + "This driver is required to be instantiated from device tree\n"); + return -EINVAL; + } + + clk = devm_clk_get(dev, "usbhs"); + if (IS_ERR(clk)) { + dev_err(dev, "Can't get USBHS clock\n"); + return PTR_ERR(clk); + } + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + base = devm_ioremap_resource(dev, res); + if (IS_ERR(base)) + return PTR_ERR(base); + + drv = devm_kzalloc(dev, sizeof(*drv), GFP_KERNEL); + if (!drv) + return -ENOMEM; + + spin_lock_init(&drv->lock); + + drv->clk = clk; + drv->base = base; + + drv->num_channels = of_get_child_count(dev->of_node); + drv->channels = devm_kcalloc(dev, drv->num_channels, + sizeof(struct rcar_gen2_channel), + GFP_KERNEL); + if (!drv->channels) + return -ENOMEM; + + for_each_child_of_node(dev->of_node, np) { + struct rcar_gen2_channel *channel = drv->channels + i; + u32 channel_num; + int error, n; + + channel->of_node = np; + channel->drv = drv; + channel->selected_phy = -1; + + error = of_property_read_u32(np, "reg", &channel_num); + if (error || channel_num > 2) { + dev_err(dev, "Invalid \"reg\" property\n"); + of_node_put(np); + return error; + } + channel->select_mask = select_mask[channel_num]; + + for (n = 0; n < PHYS_PER_CHANNEL; n++) { + struct rcar_gen2_phy *phy = &channel->phys[n]; + + phy->channel = channel; + phy->number = n; + phy->select_value = select_value[channel_num][n]; + + phy->phy = devm_phy_create(dev, NULL, + &rcar_gen2_phy_ops); + if (IS_ERR(phy->phy)) { + dev_err(dev, "Failed to create PHY\n"); + of_node_put(np); + return PTR_ERR(phy->phy); + } + phy_set_drvdata(phy->phy, phy); + } + + i++; + } + + provider = devm_of_phy_provider_register(dev, rcar_gen2_phy_xlate); + if (IS_ERR(provider)) { + dev_err(dev, "Failed to register PHY provider\n"); + return PTR_ERR(provider); + } + + dev_set_drvdata(dev, drv); + + return 0; +} + +static struct platform_driver rcar_gen2_phy_driver = { + .driver = { + .name = "phy_rcar_gen2", + .of_match_table = rcar_gen2_phy_match_table, + }, + .probe = rcar_gen2_phy_probe, +}; + +module_platform_driver(rcar_gen2_phy_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Renesas R-Car Gen2 PHY"); +MODULE_AUTHOR("Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>"); |