drivers/phy/phy-tusb1210.c

   1 /**
   2  * tusb1210.c - TUSB1210 USB ULPI PHY driver
   3  *
   4  * Copyright (C) 2015 Intel Corporation
   5  *
   6  * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12 #include <linux/module.h>
  13 #include <linux/ulpi/driver.h>
  14 #include <linux/gpio/consumer.h>
  15
  16 #include "ulpi_phy.h"
  17
  18 #define TUSB1210_VENDOR_SPECIFIC2               0x80
  19 #define TUSB1210_VENDOR_SPECIFIC2_IHSTX_SHIFT   0
  20 #define TUSB1210_VENDOR_SPECIFIC2_ZHSDRV_SHIFT  4
  21 #define TUSB1210_VENDOR_SPECIFIC2_DP_SHIFT      6
  22
  23 struct tusb1210 {
  24         struct ulpi *ulpi;
  25         struct phy *phy;
  26         struct gpio_desc *gpio_reset;
  27         struct gpio_desc *gpio_cs;
  28         u8 vendor_specific2;
  29 };
  30
  31 static int tusb1210_power_on(struct phy *phy)
  32 {
  33         struct tusb1210 *tusb = phy_get_drvdata(phy);
  34
  35         gpiod_set_value_cansleep(tusb->gpio_reset, 1);
  36         gpiod_set_value_cansleep(tusb->gpio_cs, 1);
  37
  38         /* Restore the optional eye diagram optimization value */
  39         if (tusb->vendor_specific2)
  40                 ulpi_write(tusb->ulpi, TUSB1210_VENDOR_SPECIFIC2,
  41                            tusb->vendor_specific2);
  42
  43         return 0;
  44 }
  45
  46 static int tusb1210_power_off(struct phy *phy)
  47 {
  48         struct tusb1210 *tusb = phy_get_drvdata(phy);
  49
  50         gpiod_set_value_cansleep(tusb->gpio_reset, 0);
  51         gpiod_set_value_cansleep(tusb->gpio_cs, 0);
  52
  53         return 0;
  54 }
  55
  56 static const struct phy_ops phy_ops = {
  57         .power_on = tusb1210_power_on,
  58         .power_off = tusb1210_power_off,
  59         .owner = THIS_MODULE,
  60 };
  61
  62 static int tusb1210_probe(struct ulpi *ulpi)
  63 {
  64         struct tusb1210 *tusb;
  65         u8 val, reg;
  66
  67         tusb = devm_kzalloc(&ulpi->dev, sizeof(*tusb), GFP_KERNEL);
  68         if (!tusb)
  69                 return -ENOMEM;
  70
  71         tusb->gpio_reset = devm_gpiod_get_optional(&ulpi->dev, "reset",
  72                                                    GPIOD_OUT_LOW);
  73         if (IS_ERR(tusb->gpio_reset))
  74                 return PTR_ERR(tusb->gpio_reset);
  75
  76         gpiod_set_value_cansleep(tusb->gpio_reset, 1);
  77
  78         tusb->gpio_cs = devm_gpiod_get_optional(&ulpi->dev, "cs",
  79                                                 GPIOD_OUT_LOW);
  80         if (IS_ERR(tusb->gpio_cs))
  81                 return PTR_ERR(tusb->gpio_cs);
  82
  83         gpiod_set_value_cansleep(tusb->gpio_cs, 1);
  84
  85         /*
  86          * VENDOR_SPECIFIC2 register in TUSB1210 can be used for configuring eye
  87          * diagram optimization and DP/DM swap.
  88          */
  89
  90         /* High speed output drive strength configuration */
  91         device_property_read_u8(&ulpi->dev, "ihstx", &val);
  92         reg = val << TUSB1210_VENDOR_SPECIFIC2_IHSTX_SHIFT;
  93
  94         /* High speed output impedance configuration */
  95         device_property_read_u8(&ulpi->dev, "zhsdrv", &val);
  96         reg |= val << TUSB1210_VENDOR_SPECIFIC2_ZHSDRV_SHIFT;
  97
  98         /* DP/DM swap control */
  99         device_property_read_u8(&ulpi->dev, "datapolarity", &val);
 100         reg |= val << TUSB1210_VENDOR_SPECIFIC2_DP_SHIFT;
 101
 102         if (reg) {
 103                 ulpi_write(ulpi, TUSB1210_VENDOR_SPECIFIC2, reg);
 104                 tusb->vendor_specific2 = reg;
 105         }
 106
 107         tusb->phy = ulpi_phy_create(ulpi, &phy_ops);
 108         if (IS_ERR(tusb->phy))
 109                 return PTR_ERR(tusb->phy);
 110
 111         tusb->ulpi = ulpi;
 112
 113         phy_set_drvdata(tusb->phy, tusb);
 114         ulpi_set_drvdata(ulpi, tusb);
 115         return 0;
 116 }
 117
 118 static void tusb1210_remove(struct ulpi *ulpi)
 119 {
 120         struct tusb1210 *tusb = ulpi_get_drvdata(ulpi);
 121
 122         ulpi_phy_destroy(ulpi, tusb->phy);
 123 }
 124
 125 #define TI_VENDOR_ID 0x0451
 126
 127 static const struct ulpi_device_id tusb1210_ulpi_id[] = {
 128         { TI_VENDOR_ID, 0x1507, },
 129         { },
 130 };
 131 MODULE_DEVICE_TABLE(ulpi, tusb1210_ulpi_id);
 132
 133 static struct ulpi_driver tusb1210_driver = {
 134         .id_table = tusb1210_ulpi_id,
 135         .probe = tusb1210_probe,
 136         .remove = tusb1210_remove,
 137         .driver = {
 138                 .name = "tusb1210",
 139                 .owner = THIS_MODULE,
 140         },
 141 };
 142
 143 module_ulpi_driver(tusb1210_driver);
 144
 145 MODULE_AUTHOR("Intel Corporation");
 146 MODULE_LICENSE("GPL v2");
 147 MODULE_DESCRIPTION("TUSB1210 ULPI PHY driver");