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 86 if (clk_get_rate(phy->refclk) != 24000000) 87 dev_warn(phy->dev, "nonstandard phy refclk\n"); 88 89 /* Set PLL ref clock and put phys to sleep */ 90 regmap_update_bits(phy->syscon, phy->usb_ctrl, 91 DM816X_USB_CTRL_PHYCLKSRC | 92 DM816X_USB_CTRL_PHYSLEEP1 | 93 DM816X_USB_CTRL_PHYSLEEP0, 94 0); 95 regmap_read(phy->syscon, phy->usb_ctrl, &val); 96 if ((val & 3) != 0) 97 dev_info(phy->dev, 98 "Working dm816x USB_CTRL! (0x%08x)\n", 99 val); 100 101 /* 102 * TI kernel sets these values for "symmetrical eye diagram and 103 * better signal quality" so let's assume somebody checked the 104 * values with a scope and set them here too. 105 */ 106 regmap_read(phy->syscon, phy->usbphy_ctrl, &val); 107 val |= DM816X_USBPHY_CTRL_TXRISETUNE | 108 DM816X_USBPHY_CTRL_TXVREFTUNE | 109 DM816X_USBPHY_CTRL_TXPREEMTUNE; 110 regmap_write(phy->syscon, phy->usbphy_ctrl, val); 111 112 return 0; 113 } 114 115 static const struct phy_ops ops = { 116 .init = dm816x_usb_phy_init, 117 .owner = THIS_MODULE, 118 }; 119 120 static int __maybe_unused dm816x_usb_phy_runtime_suspend(struct device *dev) 121 { 122 struct dm816x_usb_phy *phy = dev_get_drvdata(dev); 123 unsigned int mask, val; 124 int error = 0; 125 126 mask = BIT(phy->instance); 127 val = ~BIT(phy->instance); 128 error = regmap_update_bits(phy->syscon, phy->usb_ctrl, 129 mask, val); 130 if (error) 131 dev_err(phy->dev, "phy%i failed to power off\n", 132 phy->instance); 133 clk_disable(phy->refclk); 134 135 return 0; 136 } 137 138 static int __maybe_unused dm816x_usb_phy_runtime_resume(struct device *dev) 139 { 140 struct dm816x_usb_phy *phy = dev_get_drvdata(dev); 141 unsigned int mask, val; 142 int error; 143 144 error = clk_enable(phy->refclk); 145 if (error) 146 return error; 147 148 /* 149 * Note that at least dm816x rev c does not seem to do 150 * anything with the USB_CTRL register. But let's follow 151 * what the TI tree is doing in case later revisions use 152 * USB_CTRL. 153 */ 154 mask = BIT(phy->instance); 155 val = BIT(phy->instance); 156 error = regmap_update_bits(phy->syscon, phy->usb_ctrl, 157 mask, val); 158 if (error) { 159 dev_err(phy->dev, "phy%i failed to power on\n", 160 phy->instance); 161 clk_disable(phy->refclk); 162 return error; 163 } 164 165 return 0; 166 } 167 168 static UNIVERSAL_DEV_PM_OPS(dm816x_usb_phy_pm_ops, 169 dm816x_usb_phy_runtime_suspend, 170 dm816x_usb_phy_runtime_resume, 171 NULL); 172 173 #ifdef CONFIG_OF 174 static const struct of_device_id dm816x_usb_phy_id_table[] = { 175 { 176 .compatible = "ti,dm8168-usb-phy", 177 }, 178 {}, 179 }; 180 MODULE_DEVICE_TABLE(of, dm816x_usb_phy_id_table); 181 #endif 182 183 static int dm816x_usb_phy_probe(struct platform_device *pdev) 184 { 185 struct dm816x_usb_phy *phy; 186 struct resource *res; 187 struct phy *generic_phy; 188 struct phy_provider *phy_provider; 189 struct usb_otg *otg; 190 const struct of_device_id *of_id; 191 int error; 192 193 of_id = of_match_device(of_match_ptr(dm816x_usb_phy_id_table), 194 &pdev->dev); 195 if (!of_id) 196 return -EINVAL; 197 198 phy = devm_kzalloc(&pdev->dev, sizeof(*phy), GFP_KERNEL); 199 if (!phy) 200 return -ENOMEM; 201 202 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 203 if (!res) 204 return -ENOENT; 205 206 phy->syscon = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, 207 "syscon"); 208 if (IS_ERR(phy->syscon)) 209 return PTR_ERR(phy->syscon); 210 211 /* 212 * According to sprs614e.pdf, the first usb_ctrl is shared and 213 * the second instance for usb_ctrl is reserved.. Also the 214 * register bits are different from earlier TRMs. 215 */ 216 phy->usb_ctrl = 0x20; 217 phy->usbphy_ctrl = (res->start & 0xff) + 4; 218 if (phy->usbphy_ctrl == 0x2c) 219 phy->instance = 1; 220 221 otg = devm_kzalloc(&pdev->dev, sizeof(*otg), GFP_KERNEL); 222 if (!otg) 223 return -ENOMEM; 224 225 phy->dev = &pdev->dev; 226 phy->phy.dev = phy->dev; 227 phy->phy.label = "dm8168_usb_phy"; 228 phy->phy.otg = otg; 229 phy->phy.type = USB_PHY_TYPE_USB2; 230 otg->set_host = dm816x_usb_phy_set_host; 231 otg->set_peripheral = dm816x_usb_phy_set_peripheral; 232 otg->usb_phy = &phy->phy; 233 234 platform_set_drvdata(pdev, phy); 235 236 phy->refclk = devm_clk_get(phy->dev, "refclk"); 237 if (IS_ERR(phy->refclk)) 238 return PTR_ERR(phy->refclk); 239 error = clk_prepare(phy->refclk); 240 if (error) 241 return error; 242 243 pm_runtime_enable(phy->dev); 244 generic_phy = devm_phy_create(phy->dev, NULL, &ops); 245 if (IS_ERR(generic_phy)) { 246 error = PTR_ERR(generic_phy); 247 goto clk_unprepare; 248 } 249 250 phy_set_drvdata(generic_phy, phy); 251 252 phy_provider = devm_of_phy_provider_register(phy->dev, 253 of_phy_simple_xlate); 254 if (IS_ERR(phy_provider)) { 255 error = PTR_ERR(phy_provider); 256 goto clk_unprepare; 257 } 258 259 usb_add_phy_dev(&phy->phy); 260 261 return 0; 262 263 clk_unprepare: 264 pm_runtime_disable(phy->dev); 265 clk_unprepare(phy->refclk); 266 return error; 267 } 268 269 static int dm816x_usb_phy_remove(struct platform_device *pdev) 270 { 271 struct dm816x_usb_phy *phy = platform_get_drvdata(pdev); 272 273 usb_remove_phy(&phy->phy); 274 pm_runtime_disable(phy->dev); 275 clk_unprepare(phy->refclk); 276 277 return 0; 278 } 279 280 static struct platform_driver dm816x_usb_phy_driver = { 281 .probe = dm816x_usb_phy_probe, 282 .remove = dm816x_usb_phy_remove, 283 .driver = { 284 .name = "dm816x-usb-phy", 285 .pm = &dm816x_usb_phy_pm_ops, 286 .of_match_table = of_match_ptr(dm816x_usb_phy_id_table), 287 }, 288 }; 289 290 module_platform_driver(dm816x_usb_phy_driver); 291 292 MODULE_ALIAS("platform:dm816x_usb"); 293 MODULE_AUTHOR("Tony Lindgren <tony@atomide.com>"); 294 MODULE_DESCRIPTION("dm816x usb phy driver"); 295 MODULE_LICENSE("GPL v2"); 296