diff options
Diffstat (limited to 'drivers/phy/phy-dm816x-usb.c')
| -rw-r--r-- | drivers/phy/phy-dm816x-usb.c | 290 |
1 files changed, 290 insertions, 0 deletions
diff --git a/drivers/phy/phy-dm816x-usb.c b/drivers/phy/phy-dm816x-usb.c new file mode 100644 index 000000000000..7b42555ddd51 --- /dev/null +++ b/drivers/phy/phy-dm816x-usb.c @@ -0,0 +1,290 @@ +/* + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation version 2. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> + +#include <linux/slab.h> +#include <linux/of.h> +#include <linux/io.h> +#include <linux/usb/phy_companion.h> +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/pm_runtime.h> +#include <linux/delay.h> +#include <linux/phy/phy.h> +#include <linux/of_platform.h> + +#include <linux/mfd/syscon.h> + +/* + * TRM has two sets of USB_CTRL registers.. The correct register bits + * are in TRM section 24.9.8.2 USB_CTRL Register. The TRM documents the + * phy as being SR70LX Synopsys USB 2.0 OTG nanoPHY. It also seems at + * least dm816x rev c ignores writes to USB_CTRL register, but the TI + * kernel is writing to those so it's possible that later revisions + * have worknig USB_CTRL register. + * + * Also note that At least USB_CTRL register seems to be dm816x specific + * according to the TRM. It's possible that USBPHY_CTRL is more generic, + * but that would have to be checked against the SR70LX documentation + * which does not seem to be publicly available. + * + * Finally, the phy on dm814x and am335x is different from dm816x. + */ +#define DM816X_USB_CTRL_PHYCLKSRC BIT(8) /* 1 = PLL ref clock */ +#define DM816X_USB_CTRL_PHYSLEEP1 BIT(1) /* Enable the first phy */ +#define DM816X_USB_CTRL_PHYSLEEP0 BIT(0) /* Enable the second phy */ + +#define DM816X_USBPHY_CTRL_TXRISETUNE 1 +#define DM816X_USBPHY_CTRL_TXVREFTUNE 0xc +#define DM816X_USBPHY_CTRL_TXPREEMTUNE 0x2 + +struct dm816x_usb_phy { + struct regmap *syscon; + struct device *dev; + unsigned int instance; + struct clk *refclk; + struct usb_phy phy; + unsigned int usb_ctrl; /* Shared between phy0 and phy1 */ + unsigned int usbphy_ctrl; +}; + +static int dm816x_usb_phy_set_host(struct usb_otg *otg, struct usb_bus *host) +{ + otg->host = host; + if (!host) + otg->state = OTG_STATE_UNDEFINED; + + return 0; +} + +static int dm816x_usb_phy_set_peripheral(struct usb_otg *otg, + struct usb_gadget *gadget) +{ + otg->gadget = gadget; + if (!gadget) + otg->state = OTG_STATE_UNDEFINED; + + return 0; +} + +static int dm816x_usb_phy_init(struct phy *x) +{ + struct dm816x_usb_phy *phy = phy_get_drvdata(x); + unsigned int val; + int error; + + if (clk_get_rate(phy->refclk) != 24000000) + dev_warn(phy->dev, "nonstandard phy refclk\n"); + + /* Set PLL ref clock and put phys to sleep */ + error = regmap_update_bits(phy->syscon, phy->usb_ctrl, + DM816X_USB_CTRL_PHYCLKSRC | + DM816X_USB_CTRL_PHYSLEEP1 | + DM816X_USB_CTRL_PHYSLEEP0, + 0); + regmap_read(phy->syscon, phy->usb_ctrl, &val); + if ((val & 3) != 0) + dev_info(phy->dev, + "Working dm816x USB_CTRL! (0x%08x)\n", + val); + + /* + * TI kernel sets these values for "symmetrical eye diagram and + * better signal quality" so let's assume somebody checked the + * values with a scope and set them here too. + */ + regmap_read(phy->syscon, phy->usbphy_ctrl, &val); + val |= DM816X_USBPHY_CTRL_TXRISETUNE | + DM816X_USBPHY_CTRL_TXVREFTUNE | + DM816X_USBPHY_CTRL_TXPREEMTUNE; + regmap_write(phy->syscon, phy->usbphy_ctrl, val); + + return 0; +} + +static struct phy_ops ops = { + .init = dm816x_usb_phy_init, + .owner = THIS_MODULE, +}; + +static int dm816x_usb_phy_runtime_suspend(struct device *dev) +{ + struct dm816x_usb_phy *phy = dev_get_drvdata(dev); + unsigned int mask, val; + int error = 0; + + mask = BIT(phy->instance); + val = ~BIT(phy->instance); + error = regmap_update_bits(phy->syscon, phy->usb_ctrl, + mask, val); + if (error) + dev_err(phy->dev, "phy%i failed to power off\n", + phy->instance); + clk_disable(phy->refclk); + + return 0; +} + +static int dm816x_usb_phy_runtime_resume(struct device *dev) +{ + struct dm816x_usb_phy *phy = dev_get_drvdata(dev); + unsigned int mask, val; + int error; + + error = clk_enable(phy->refclk); + if (error) + return error; + + /* + * Note that at least dm816x rev c does not seem to do + * anything with the USB_CTRL register. But let's follow + * what the TI tree is doing in case later revisions use + * USB_CTRL. + */ + mask = BIT(phy->instance); + val = BIT(phy->instance); + error = regmap_update_bits(phy->syscon, phy->usb_ctrl, + mask, val); + if (error) { + dev_err(phy->dev, "phy%i failed to power on\n", + phy->instance); + clk_disable(phy->refclk); + return error; + } + + return 0; +} + +static UNIVERSAL_DEV_PM_OPS(dm816x_usb_phy_pm_ops, + dm816x_usb_phy_runtime_suspend, + dm816x_usb_phy_runtime_resume, + NULL); + +#ifdef CONFIG_OF +static const struct of_device_id dm816x_usb_phy_id_table[] = { + { + .compatible = "ti,dm8168-usb-phy", + }, + {}, +}; +MODULE_DEVICE_TABLE(of, dm816x_usb_phy_id_table); +#endif + +static int dm816x_usb_phy_probe(struct platform_device *pdev) +{ + struct dm816x_usb_phy *phy; + struct resource *res; + struct phy *generic_phy; + struct phy_provider *phy_provider; + struct usb_otg *otg; + const struct of_device_id *of_id; + const struct usb_phy_data *phy_data; + int error; + + of_id = of_match_device(of_match_ptr(dm816x_usb_phy_id_table), + &pdev->dev); + if (!of_id) + return -EINVAL; + + phy = devm_kzalloc(&pdev->dev, sizeof(*phy), GFP_KERNEL); + if (!phy) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -ENOENT; + + phy->syscon = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, + "syscon"); + if (IS_ERR(phy->syscon)) + return PTR_ERR(phy->syscon); + + /* + * According to sprs614e.pdf, the first usb_ctrl is shared and + * the second instance for usb_ctrl is reserved.. Also the + * register bits are different from earlier TRMs. + */ + phy->usb_ctrl = 0x20; + phy->usbphy_ctrl = (res->start & 0xff) + 4; + if (phy->usbphy_ctrl == 0x2c) + phy->instance = 1; + + phy_data = of_id->data; + + otg = devm_kzalloc(&pdev->dev, sizeof(*otg), GFP_KERNEL); + if (!otg) + return -ENOMEM; + + phy->dev = &pdev->dev; + phy->phy.dev = phy->dev; + phy->phy.label = "dm8168_usb_phy"; + phy->phy.otg = otg; + phy->phy.type = USB_PHY_TYPE_USB2; + otg->set_host = dm816x_usb_phy_set_host; + otg->set_peripheral = dm816x_usb_phy_set_peripheral; + otg->usb_phy = &phy->phy; + + platform_set_drvdata(pdev, phy); + + phy->refclk = devm_clk_get(phy->dev, "refclk"); + if (IS_ERR(phy->refclk)) + return PTR_ERR(phy->refclk); + error = clk_prepare(phy->refclk); + if (error) + return error; + + pm_runtime_enable(phy->dev); + generic_phy = devm_phy_create(phy->dev, NULL, &ops); + if (IS_ERR(generic_phy)) + return PTR_ERR(generic_phy); + + phy_set_drvdata(generic_phy, phy); + + phy_provider = devm_of_phy_provider_register(phy->dev, + of_phy_simple_xlate); + if (IS_ERR(phy_provider)) + return PTR_ERR(phy_provider); + + usb_add_phy_dev(&phy->phy); + + return 0; +} + +static int dm816x_usb_phy_remove(struct platform_device *pdev) +{ + struct dm816x_usb_phy *phy = platform_get_drvdata(pdev); + + usb_remove_phy(&phy->phy); + pm_runtime_disable(phy->dev); + clk_unprepare(phy->refclk); + + return 0; +} + +static struct platform_driver dm816x_usb_phy_driver = { + .probe = dm816x_usb_phy_probe, + .remove = dm816x_usb_phy_remove, + .driver = { + .name = "dm816x-usb-phy", + .pm = &dm816x_usb_phy_pm_ops, + .of_match_table = of_match_ptr(dm816x_usb_phy_id_table), + }, +}; + +module_platform_driver(dm816x_usb_phy_driver); + +MODULE_ALIAS("platform:dm816x_usb"); +MODULE_AUTHOR("Tony Lindgren <tony@atomide.com>"); +MODULE_DESCRIPTION("dm816x usb phy driver"); +MODULE_LICENSE("GPL v2"); |