1 /* 2 * This program is free software; you can redistribute it and/or 3 * modify it under the terms of the GNU General Public License as 4 * published by the Free Software Foundation version 2. 5 * 6 * This program is distributed "as is" WITHOUT ANY WARRANTY of any 7 * kind, whether express or implied; without even the implied warranty 8 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 9 * GNU General Public License for more details. 10 */ 11 12 #include <linux/module.h> 13 #include <linux/platform_device.h> 14 #include <linux/regmap.h> 15 16 #include <linux/slab.h> 17 #include <linux/of.h> 18 #include <linux/io.h> 19 #include <linux/usb/phy_companion.h> 20 #include <linux/clk.h> 21 #include <linux/err.h> 22 #include <linux/pm_runtime.h> 23 #include <linux/delay.h> 24 #include <linux/phy/phy.h> 25 #include <linux/of_platform.h> 26 27 #include <linux/mfd/syscon.h> 28 29 /* 30 * TRM has two sets of USB_CTRL registers.. The correct register bits 31 * are in TRM section 24.9.8.2 USB_CTRL Register. The TRM documents the 32 * phy as being SR70LX Synopsys USB 2.0 OTG nanoPHY. It also seems at 33 * least dm816x rev c ignores writes to USB_CTRL register, but the TI 34 * kernel is writing to those so it's possible that later revisions 35 * have worknig USB_CTRL register. 36 * 37 * Also note that At least USB_CTRL register seems to be dm816x specific 38 * according to the TRM. It's possible that USBPHY_CTRL is more generic, 39 * but that would have to be checked against the SR70LX documentation 40 * which does not seem to be publicly available. 41 * 42 * Finally, the phy on dm814x and am335x is different from dm816x. 43 */ 44 #define DM816X_USB_CTRL_PHYCLKSRC BIT(8) /* 1 = PLL ref clock */ 45 #define DM816X_USB_CTRL_PHYSLEEP1 BIT(1) /* Enable the first phy */ 46 #define DM816X_USB_CTRL_PHYSLEEP0 BIT(0) /* Enable the second phy */ 47 48 #define DM816X_USBPHY_CTRL_TXRISETUNE 1 49 #define DM816X_USBPHY_CTRL_TXVREFTUNE 0xc 50 #define DM816X_USBPHY_CTRL_TXPREEMTUNE 0x2 51 52 struct dm816x_usb_phy { 53 struct regmap *syscon; 54 struct device *dev; 55 unsigned int instance; 56 struct clk *refclk; 57 struct usb_phy phy; 58 unsigned int usb_ctrl; /* Shared between phy0 and phy1 */ 59 unsigned int usbphy_ctrl; 60 }; 61 62 static int dm816x_usb_phy_set_host(struct usb_otg *otg, struct usb_bus *host) 63 { 64 otg->host = host; 65 if (!host) 66 otg->state = OTG_STATE_UNDEFINED; 67 68 return 0; 69 } 70 71 static int dm816x_usb_phy_set_peripheral(struct usb_otg *otg, 72 struct usb_gadget *gadget) 73 { 74 otg->gadget = gadget; 75 if (!gadget) 76 otg->state = OTG_STATE_UNDEFINED; 77 78 return 0; 79 } 80 81 static int dm816x_usb_phy_init(struct phy *x) 82 { 83 struct dm816x_usb_phy *phy = phy_get_drvdata(x); 84 unsigned int val; 85 int error; 86 87 if (clk_get_rate(phy->refclk) != 24000000) 88 dev_warn(phy->dev, "nonstandard phy refclk\n"); 89 90 /* Set PLL ref clock and put phys to sleep */ 91 error = regmap_update_bits(phy->syscon, phy->usb_ctrl, 92 DM816X_USB_CTRL_PHYCLKSRC | 93 DM816X_USB_CTRL_PHYSLEEP1 | 94 DM816X_USB_CTRL_PHYSLEEP0, 95 0); 96 regmap_read(phy->syscon, phy->usb_ctrl, &val); 97 if ((val & 3) != 0) 98 dev_info(phy->dev, 99 "Working dm816x USB_CTRL! (0x%08x)\n", 100 val); 101 102 /* 103 * TI kernel sets these values for "symmetrical eye diagram and 104 * better signal quality" so let's assume somebody checked the 105 * values with a scope and set them here too. 106 */ 107 regmap_read(phy->syscon, phy->usbphy_ctrl, &val); 108 val |= DM816X_USBPHY_CTRL_TXRISETUNE | 109 DM816X_USBPHY_CTRL_TXVREFTUNE | 110 DM816X_USBPHY_CTRL_TXPREEMTUNE; 111 regmap_write(phy->syscon, phy->usbphy_ctrl, val); 112 113 return 0; 114 } 115 116 static const struct phy_ops ops = { 117 .init = dm816x_usb_phy_init, 118 .owner = THIS_MODULE, 119 }; 120 121 static int __maybe_unused dm816x_usb_phy_runtime_suspend(struct device *dev) 122 { 123 struct dm816x_usb_phy *phy = dev_get_drvdata(dev); 124 unsigned int mask, val; 125 int error = 0; 126 127 mask = BIT(phy->instance); 128 val = ~BIT(phy->instance); 129 error = regmap_update_bits(phy->syscon, phy->usb_ctrl, 130 mask, val); 131 if (error) 132 dev_err(phy->dev, "phy%i failed to power off\n", 133 phy->instance); 134 clk_disable(phy->refclk); 135 136 return 0; 137 } 138 139 static int __maybe_unused dm816x_usb_phy_runtime_resume(struct device *dev) 140 { 141 struct dm816x_usb_phy *phy = dev_get_drvdata(dev); 142 unsigned int mask, val; 143 int error; 144 145 error = clk_enable(phy->refclk); 146 if (error) 147 return error; 148 149 /* 150 * Note that at least dm816x rev c does not seem to do 151 * anything with the USB_CTRL register. But let's follow 152 * what the TI tree is doing in case later revisions use 153 * USB_CTRL. 154 */ 155 mask = BIT(phy->instance); 156 val = BIT(phy->instance); 157 error = regmap_update_bits(phy->syscon, phy->usb_ctrl, 158 mask, val); 159 if (error) { 160 dev_err(phy->dev, "phy%i failed to power on\n", 161 phy->instance); 162 clk_disable(phy->refclk); 163 return error; 164 } 165 166 return 0; 167 } 168 169 static UNIVERSAL_DEV_PM_OPS(dm816x_usb_phy_pm_ops, 170 dm816x_usb_phy_runtime_suspend, 171 dm816x_usb_phy_runtime_resume, 172 NULL); 173 174 #ifdef CONFIG_OF 175 static const struct of_device_id dm816x_usb_phy_id_table[] = { 176 { 177 .compatible = "ti,dm8168-usb-phy", 178 }, 179 {}, 180 }; 181 MODULE_DEVICE_TABLE(of, dm816x_usb_phy_id_table); 182 #endif 183 184 static int dm816x_usb_phy_probe(struct platform_device *pdev) 185 { 186 struct dm816x_usb_phy *phy; 187 struct resource *res; 188 struct phy *generic_phy; 189 struct phy_provider *phy_provider; 190 struct usb_otg *otg; 191 const struct of_device_id *of_id; 192 int error; 193 194 of_id = of_match_device(of_match_ptr(dm816x_usb_phy_id_table), 195 &pdev->dev); 196 if (!of_id) 197 return -EINVAL; 198 199 phy = devm_kzalloc(&pdev->dev, sizeof(*phy), GFP_KERNEL); 200 if (!phy) 201 return -ENOMEM; 202 203 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 204 if (!res) 205 return -ENOENT; 206 207 phy->syscon = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, 208 "syscon"); 209 if (IS_ERR(phy->syscon)) 210 return PTR_ERR(phy->syscon); 211 212 /* 213 * According to sprs614e.pdf, the first usb_ctrl is shared and 214 * the second instance for usb_ctrl is reserved.. Also the 215 * register bits are different from earlier TRMs. 216 */ 217 phy->usb_ctrl = 0x20; 218 phy->usbphy_ctrl = (res->start & 0xff) + 4; 219 if (phy->usbphy_ctrl == 0x2c) 220 phy->instance = 1; 221 222 otg = devm_kzalloc(&pdev->dev, sizeof(*otg), GFP_KERNEL); 223 if (!otg) 224 return -ENOMEM; 225 226 phy->dev = &pdev->dev; 227 phy->phy.dev = phy->dev; 228 phy->phy.label = "dm8168_usb_phy"; 229 phy->phy.otg = otg; 230 phy->phy.type = USB_PHY_TYPE_USB2; 231 otg->set_host = dm816x_usb_phy_set_host; 232 otg->set_peripheral = dm816x_usb_phy_set_peripheral; 233 otg->usb_phy = &phy->phy; 234 235 platform_set_drvdata(pdev, phy); 236 237 phy->refclk = devm_clk_get(phy->dev, "refclk"); 238 if (IS_ERR(phy->refclk)) 239 return PTR_ERR(phy->refclk); 240 error = clk_prepare(phy->refclk); 241 if (error) 242 return error; 243 244 pm_runtime_enable(phy->dev); 245 generic_phy = devm_phy_create(phy->dev, NULL, &ops); 246 if (IS_ERR(generic_phy)) 247 return PTR_ERR(generic_phy); 248 249 phy_set_drvdata(generic_phy, phy); 250 251 phy_provider = devm_of_phy_provider_register(phy->dev, 252 of_phy_simple_xlate); 253 if (IS_ERR(phy_provider)) 254 return PTR_ERR(phy_provider); 255 256 usb_add_phy_dev(&phy->phy); 257 258 return 0; 259 } 260 261 static int dm816x_usb_phy_remove(struct platform_device *pdev) 262 { 263 struct dm816x_usb_phy *phy = platform_get_drvdata(pdev); 264 265 usb_remove_phy(&phy->phy); 266 pm_runtime_disable(phy->dev); 267 clk_unprepare(phy->refclk); 268 269 return 0; 270 } 271 272 static struct platform_driver dm816x_usb_phy_driver = { 273 .probe = dm816x_usb_phy_probe, 274 .remove = dm816x_usb_phy_remove, 275 .driver = { 276 .name = "dm816x-usb-phy", 277 .pm = &dm816x_usb_phy_pm_ops, 278 .of_match_table = of_match_ptr(dm816x_usb_phy_id_table), 279 }, 280 }; 281 282 module_platform_driver(dm816x_usb_phy_driver); 283 284 MODULE_ALIAS("platform:dm816x_usb"); 285 MODULE_AUTHOR("Tony Lindgren <tony@atomide.com>"); 286 MODULE_DESCRIPTION("dm816x usb phy driver"); 287 MODULE_LICENSE("GPL v2"); 288