Tom Rini | 83d290c | 2018-05-06 17:58:06 -0400 | [diff] [blame^] | 1 | // SPDX-License-Identifier: GPL-2.0+ |
Simon Glass | bcd5dff | 2015-07-02 18:16:09 -0600 | [diff] [blame] | 2 | /* |
| 3 | * Copyright (C) 2015 Google, Inc |
| 4 | * Written by Simon Glass <sjg@chromium.org> |
Simon Glass | bcd5dff | 2015-07-02 18:16:09 -0600 | [diff] [blame] | 5 | */ |
| 6 | |
| 7 | #include <common.h> |
| 8 | #include <dm.h> |
| 9 | #include <errno.h> |
| 10 | #include <i2c.h> |
| 11 | #include <video_bridge.h> |
| 12 | #include <power/regulator.h> |
| 13 | |
| 14 | DECLARE_GLOBAL_DATA_PTR; |
| 15 | |
| 16 | /* |
| 17 | * Initialisation of the chip is a process of writing certain values into |
| 18 | * certain registers over i2c bus. The chip in fact responds to a range of |
| 19 | * addresses on the i2c bus, so for each written value three parameters are |
| 20 | * required: i2c address, register address and the actual value. |
| 21 | * |
| 22 | * The base address is derived from the device tree, but oddly the chip |
| 23 | * responds on several addresses with different register sets for each. |
| 24 | */ |
| 25 | |
| 26 | /** |
| 27 | * ps8622_write() Write a PS8622 eDP bridge i2c register |
| 28 | * |
| 29 | * @param dev I2C device |
| 30 | * @param addr_off offset from the i2c base address for ps8622 |
| 31 | * @param reg_addr register address to write |
| 32 | * @param value value to be written |
| 33 | * @return 0 on success, non-0 on failure |
| 34 | */ |
| 35 | static int ps8622_write(struct udevice *dev, unsigned addr_off, |
| 36 | unsigned char reg_addr, unsigned char value) |
| 37 | { |
| 38 | struct dm_i2c_chip *chip = dev_get_parent_platdata(dev); |
| 39 | uint8_t buf[2]; |
| 40 | struct i2c_msg msg; |
| 41 | int ret; |
| 42 | |
| 43 | msg.addr = chip->chip_addr + addr_off; |
| 44 | msg.flags = 0; |
| 45 | buf[0] = reg_addr; |
| 46 | buf[1] = value; |
| 47 | msg.buf = buf; |
| 48 | msg.len = 2; |
| 49 | ret = dm_i2c_xfer(dev, &msg, 1); |
| 50 | if (ret) { |
| 51 | debug("%s: write failed, reg=%#x, value=%#x, ret=%d\n", |
| 52 | __func__, reg_addr, value, ret); |
| 53 | return ret; |
| 54 | } |
| 55 | |
| 56 | return 0; |
| 57 | } |
| 58 | |
| 59 | static int ps8622_set_backlight(struct udevice *dev, int percent) |
| 60 | { |
| 61 | int level = percent * 255 / 100; |
| 62 | |
| 63 | debug("%s: level=%d\n", __func__, level); |
| 64 | return ps8622_write(dev, 0x01, 0xa7, level); |
| 65 | } |
| 66 | |
| 67 | static int ps8622_attach(struct udevice *dev) |
| 68 | { |
| 69 | const uint8_t *params; |
| 70 | struct udevice *reg; |
| 71 | int ret, i, len; |
| 72 | |
| 73 | debug("%s: %s\n", __func__, dev->name); |
| 74 | /* set the LDO providing the 1.2V rail to the Parade bridge */ |
| 75 | ret = uclass_get_device_by_phandle(UCLASS_REGULATOR, dev, |
| 76 | "power-supply", ®); |
| 77 | if (!ret) { |
| 78 | ret = regulator_autoset(reg); |
| 79 | } else if (ret != -ENOENT) { |
| 80 | debug("%s: Failed to enable power: ret=%d\n", __func__, ret); |
| 81 | return ret; |
| 82 | } |
| 83 | |
| 84 | ret = video_bridge_set_active(dev, true); |
| 85 | if (ret) |
| 86 | return ret; |
| 87 | |
Simon Glass | e160f7d | 2017-01-17 16:52:55 -0700 | [diff] [blame] | 88 | params = fdt_getprop(gd->fdt_blob, dev_of_offset(dev), "parade,regs", |
| 89 | &len); |
Simon Glass | bcd5dff | 2015-07-02 18:16:09 -0600 | [diff] [blame] | 90 | if (!params || len % 3) { |
| 91 | debug("%s: missing/invalid params=%p, len=%x\n", __func__, |
| 92 | params, len); |
| 93 | return -EINVAL; |
| 94 | } |
| 95 | |
| 96 | /* need to wait 20ms after power on before doing I2C writes */ |
| 97 | mdelay(20); |
| 98 | for (i = 0; i < len; i += 3) { |
| 99 | ret = ps8622_write(dev, params[i + 0], params[i + 1], |
| 100 | params[i + 2]); |
| 101 | if (ret) |
| 102 | return ret; |
| 103 | } |
| 104 | |
| 105 | return 0; |
| 106 | } |
| 107 | |
| 108 | static int ps8622_probe(struct udevice *dev) |
| 109 | { |
| 110 | debug("%s\n", __func__); |
| 111 | if (device_get_uclass_id(dev->parent) != UCLASS_I2C) |
| 112 | return -EPROTONOSUPPORT; |
| 113 | |
| 114 | return 0; |
| 115 | } |
| 116 | |
| 117 | struct video_bridge_ops ps8622_ops = { |
| 118 | .attach = ps8622_attach, |
| 119 | .set_backlight = ps8622_set_backlight, |
| 120 | }; |
| 121 | |
| 122 | static const struct udevice_id ps8622_ids[] = { |
| 123 | { .compatible = "parade,ps8622", }, |
| 124 | { .compatible = "parade,ps8625", }, |
| 125 | { } |
| 126 | }; |
| 127 | |
| 128 | U_BOOT_DRIVER(parade_ps8622) = { |
| 129 | .name = "parade_ps8622", |
| 130 | .id = UCLASS_VIDEO_BRIDGE, |
| 131 | .of_match = ps8622_ids, |
| 132 | .probe = ps8622_probe, |
| 133 | .ops = &ps8622_ops, |
| 134 | }; |