1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * cdns3-ti.c - TI specific Glue layer for Cadence USB Controller 4 * 5 * Copyright (C) 2019 Texas Instruments Incorporated - https://www.ti.com 6 */ 7 8 #include <linux/bits.h> 9 #include <linux/clk.h> 10 #include <linux/module.h> 11 #include <linux/kernel.h> 12 #include <linux/interrupt.h> 13 #include <linux/platform_device.h> 14 #include <linux/dma-mapping.h> 15 #include <linux/io.h> 16 #include <linux/of_platform.h> 17 #include <linux/pm_runtime.h> 18 #include <linux/property.h> 19 20 /* USB Wrapper register offsets */ 21 #define USBSS_PID 0x0 22 #define USBSS_W1 0x4 23 #define USBSS_STATIC_CONFIG 0x8 24 #define USBSS_PHY_TEST 0xc 25 #define USBSS_DEBUG_CTRL 0x10 26 #define USBSS_DEBUG_INFO 0x14 27 #define USBSS_DEBUG_LINK_STATE 0x18 28 #define USBSS_DEVICE_CTRL 0x1c 29 30 /* Wrapper 1 register bits */ 31 #define USBSS_W1_PWRUP_RST BIT(0) 32 #define USBSS_W1_OVERCURRENT_SEL BIT(8) 33 #define USBSS_W1_MODESTRAP_SEL BIT(9) 34 #define USBSS_W1_OVERCURRENT BIT(16) 35 #define USBSS_W1_MODESTRAP_MASK GENMASK(18, 17) 36 #define USBSS_W1_MODESTRAP_SHIFT 17 37 #define USBSS_W1_USB2_ONLY BIT(19) 38 39 /* Static config register bits */ 40 #define USBSS1_STATIC_PLL_REF_SEL_MASK GENMASK(8, 5) 41 #define USBSS1_STATIC_PLL_REF_SEL_SHIFT 5 42 #define USBSS1_STATIC_LOOPBACK_MODE_MASK GENMASK(4, 3) 43 #define USBSS1_STATIC_LOOPBACK_MODE_SHIFT 3 44 #define USBSS1_STATIC_VBUS_SEL_MASK GENMASK(2, 1) 45 #define USBSS1_STATIC_VBUS_SEL_SHIFT 1 46 #define USBSS1_STATIC_LANE_REVERSE BIT(0) 47 48 /* Modestrap modes */ 49 enum modestrap_mode { USBSS_MODESTRAP_MODE_NONE, 50 USBSS_MODESTRAP_MODE_HOST, 51 USBSS_MODESTRAP_MODE_PERIPHERAL}; 52 53 struct cdns_ti { 54 struct device *dev; 55 void __iomem *usbss; 56 unsigned usb2_only:1; 57 unsigned vbus_divider:1; 58 struct clk *usb2_refclk; 59 struct clk *lpm_clk; 60 }; 61 62 static const int cdns_ti_rate_table[] = { /* in KHZ */ 63 9600, 64 10000, 65 12000, 66 19200, 67 20000, 68 24000, 69 25000, 70 26000, 71 38400, 72 40000, 73 58000, 74 50000, 75 52000, 76 }; 77 78 static inline u32 cdns_ti_readl(struct cdns_ti *data, u32 offset) 79 { 80 return readl(data->usbss + offset); 81 } 82 83 static inline void cdns_ti_writel(struct cdns_ti *data, u32 offset, u32 value) 84 { 85 writel(value, data->usbss + offset); 86 } 87 88 static int cdns_ti_probe(struct platform_device *pdev) 89 { 90 struct device *dev = &pdev->dev; 91 struct device_node *node = pdev->dev.of_node; 92 struct cdns_ti *data; 93 int error; 94 u32 reg; 95 int rate_code, i; 96 unsigned long rate; 97 98 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); 99 if (!data) 100 return -ENOMEM; 101 102 platform_set_drvdata(pdev, data); 103 104 data->dev = dev; 105 106 data->usbss = devm_platform_ioremap_resource(pdev, 0); 107 if (IS_ERR(data->usbss)) { 108 dev_err(dev, "can't map IOMEM resource\n"); 109 return PTR_ERR(data->usbss); 110 } 111 112 data->usb2_refclk = devm_clk_get(dev, "ref"); 113 if (IS_ERR(data->usb2_refclk)) { 114 dev_err(dev, "can't get usb2_refclk\n"); 115 return PTR_ERR(data->usb2_refclk); 116 } 117 118 data->lpm_clk = devm_clk_get(dev, "lpm"); 119 if (IS_ERR(data->lpm_clk)) { 120 dev_err(dev, "can't get lpm_clk\n"); 121 return PTR_ERR(data->lpm_clk); 122 } 123 124 rate = clk_get_rate(data->usb2_refclk); 125 rate /= 1000; /* To KHz */ 126 for (i = 0; i < ARRAY_SIZE(cdns_ti_rate_table); i++) { 127 if (cdns_ti_rate_table[i] == rate) 128 break; 129 } 130 131 if (i == ARRAY_SIZE(cdns_ti_rate_table)) { 132 dev_err(dev, "unsupported usb2_refclk rate: %lu KHz\n", rate); 133 return -EINVAL; 134 } 135 136 rate_code = i; 137 138 pm_runtime_enable(dev); 139 error = pm_runtime_get_sync(dev); 140 if (error < 0) { 141 dev_err(dev, "pm_runtime_get_sync failed: %d\n", error); 142 goto err; 143 } 144 145 /* assert RESET */ 146 reg = cdns_ti_readl(data, USBSS_W1); 147 reg &= ~USBSS_W1_PWRUP_RST; 148 cdns_ti_writel(data, USBSS_W1, reg); 149 150 /* set static config */ 151 reg = cdns_ti_readl(data, USBSS_STATIC_CONFIG); 152 reg &= ~USBSS1_STATIC_PLL_REF_SEL_MASK; 153 reg |= rate_code << USBSS1_STATIC_PLL_REF_SEL_SHIFT; 154 155 reg &= ~USBSS1_STATIC_VBUS_SEL_MASK; 156 data->vbus_divider = device_property_read_bool(dev, "ti,vbus-divider"); 157 if (data->vbus_divider) 158 reg |= 1 << USBSS1_STATIC_VBUS_SEL_SHIFT; 159 160 cdns_ti_writel(data, USBSS_STATIC_CONFIG, reg); 161 reg = cdns_ti_readl(data, USBSS_STATIC_CONFIG); 162 163 /* set USB2_ONLY mode if requested */ 164 reg = cdns_ti_readl(data, USBSS_W1); 165 data->usb2_only = device_property_read_bool(dev, "ti,usb2-only"); 166 if (data->usb2_only) 167 reg |= USBSS_W1_USB2_ONLY; 168 169 /* set default modestrap */ 170 reg |= USBSS_W1_MODESTRAP_SEL; 171 reg &= ~USBSS_W1_MODESTRAP_MASK; 172 reg |= USBSS_MODESTRAP_MODE_NONE << USBSS_W1_MODESTRAP_SHIFT; 173 cdns_ti_writel(data, USBSS_W1, reg); 174 175 /* de-assert RESET */ 176 reg |= USBSS_W1_PWRUP_RST; 177 cdns_ti_writel(data, USBSS_W1, reg); 178 179 error = of_platform_populate(node, NULL, NULL, dev); 180 if (error) { 181 dev_err(dev, "failed to create children: %d\n", error); 182 goto err; 183 } 184 185 return 0; 186 187 err: 188 pm_runtime_put_sync(data->dev); 189 pm_runtime_disable(data->dev); 190 191 return error; 192 } 193 194 static int cdns_ti_remove_core(struct device *dev, void *c) 195 { 196 struct platform_device *pdev = to_platform_device(dev); 197 198 platform_device_unregister(pdev); 199 200 return 0; 201 } 202 203 static void cdns_ti_remove(struct platform_device *pdev) 204 { 205 struct device *dev = &pdev->dev; 206 207 device_for_each_child(dev, NULL, cdns_ti_remove_core); 208 pm_runtime_put_sync(dev); 209 pm_runtime_disable(dev); 210 211 platform_set_drvdata(pdev, NULL); 212 } 213 214 static const struct of_device_id cdns_ti_of_match[] = { 215 { .compatible = "ti,j721e-usb", }, 216 { .compatible = "ti,am64-usb", }, 217 {}, 218 }; 219 MODULE_DEVICE_TABLE(of, cdns_ti_of_match); 220 221 static struct platform_driver cdns_ti_driver = { 222 .probe = cdns_ti_probe, 223 .remove_new = cdns_ti_remove, 224 .driver = { 225 .name = "cdns3-ti", 226 .of_match_table = cdns_ti_of_match, 227 }, 228 }; 229 230 module_platform_driver(cdns_ti_driver); 231 232 MODULE_ALIAS("platform:cdns3-ti"); 233 MODULE_AUTHOR("Roger Quadros <rogerq@ti.com>"); 234 MODULE_LICENSE("GPL v2"); 235 MODULE_DESCRIPTION("Cadence USB3 TI Glue Layer"); 236