1*65fba592SSimon Glass /* 2*65fba592SSimon Glass * Copyright (c) 2016 Google, Inc 3*65fba592SSimon Glass * Written by Simon Glass <sjg@chromium.org> 4*65fba592SSimon Glass * 5*65fba592SSimon Glass * SPDX-License-Identifier: GPL-2.0+ 6*65fba592SSimon Glass */ 7*65fba592SSimon Glass 8*65fba592SSimon Glass #include <common.h> 9*65fba592SSimon Glass #include <dm.h> 10*65fba592SSimon Glass #include <backlight.h> 11*65fba592SSimon Glass #include <pwm.h> 12*65fba592SSimon Glass #include <asm/gpio.h> 13*65fba592SSimon Glass #include <power/regulator.h> 14*65fba592SSimon Glass 15*65fba592SSimon Glass DECLARE_GLOBAL_DATA_PTR; 16*65fba592SSimon Glass 17*65fba592SSimon Glass struct pwm_backlight_priv { 18*65fba592SSimon Glass struct udevice *reg; 19*65fba592SSimon Glass struct gpio_desc enable; 20*65fba592SSimon Glass struct udevice *pwm; 21*65fba592SSimon Glass uint channel; 22*65fba592SSimon Glass uint period_ns; 23*65fba592SSimon Glass uint default_level; 24*65fba592SSimon Glass uint min_level; 25*65fba592SSimon Glass uint max_level; 26*65fba592SSimon Glass }; 27*65fba592SSimon Glass 28*65fba592SSimon Glass static int pwm_backlight_enable(struct udevice *dev) 29*65fba592SSimon Glass { 30*65fba592SSimon Glass struct pwm_backlight_priv *priv = dev_get_priv(dev); 31*65fba592SSimon Glass uint duty_cycle; 32*65fba592SSimon Glass int ret; 33*65fba592SSimon Glass 34*65fba592SSimon Glass debug("%s: Enable '%s', regulator '%s'\n", __func__, dev->name, 35*65fba592SSimon Glass priv->reg->name); 36*65fba592SSimon Glass ret = regulator_set_enable(priv->reg, true); 37*65fba592SSimon Glass if (ret) { 38*65fba592SSimon Glass debug("%s: Cannot enable regulator for PWM '%s'\n", __func__, 39*65fba592SSimon Glass dev->name); 40*65fba592SSimon Glass return ret; 41*65fba592SSimon Glass } 42*65fba592SSimon Glass mdelay(120); 43*65fba592SSimon Glass 44*65fba592SSimon Glass duty_cycle = priv->period_ns * (priv->default_level - priv->min_level) / 45*65fba592SSimon Glass (priv->max_level - priv->min_level + 1); 46*65fba592SSimon Glass ret = pwm_set_config(priv->pwm, priv->channel, priv->period_ns, 47*65fba592SSimon Glass duty_cycle); 48*65fba592SSimon Glass if (ret) 49*65fba592SSimon Glass return ret; 50*65fba592SSimon Glass ret = pwm_set_enable(priv->pwm, priv->channel, true); 51*65fba592SSimon Glass if (ret) 52*65fba592SSimon Glass return ret; 53*65fba592SSimon Glass mdelay(10); 54*65fba592SSimon Glass dm_gpio_set_value(&priv->enable, 1); 55*65fba592SSimon Glass 56*65fba592SSimon Glass return 0; 57*65fba592SSimon Glass } 58*65fba592SSimon Glass 59*65fba592SSimon Glass static int pwm_backlight_ofdata_to_platdata(struct udevice *dev) 60*65fba592SSimon Glass { 61*65fba592SSimon Glass struct pwm_backlight_priv *priv = dev_get_priv(dev); 62*65fba592SSimon Glass struct fdtdec_phandle_args args; 63*65fba592SSimon Glass const void *blob = gd->fdt_blob; 64*65fba592SSimon Glass int node = dev->of_offset; 65*65fba592SSimon Glass int index, ret, count, len; 66*65fba592SSimon Glass const u32 *cell; 67*65fba592SSimon Glass 68*65fba592SSimon Glass ret = uclass_get_device_by_phandle(UCLASS_REGULATOR, dev, 69*65fba592SSimon Glass "power-supply", &priv->reg); 70*65fba592SSimon Glass if (ret) { 71*65fba592SSimon Glass debug("%s: Cannot get power supply: ret=%d\n", __func__, ret); 72*65fba592SSimon Glass return ret; 73*65fba592SSimon Glass } 74*65fba592SSimon Glass ret = gpio_request_by_name(dev, "enable-gpios", 0, &priv->enable, 75*65fba592SSimon Glass GPIOD_IS_OUT); 76*65fba592SSimon Glass if (ret) { 77*65fba592SSimon Glass debug("%s: Warning: cannot get enable GPIO: ret=%d\n", 78*65fba592SSimon Glass __func__, ret); 79*65fba592SSimon Glass if (ret != -ENOENT) 80*65fba592SSimon Glass return ret; 81*65fba592SSimon Glass } 82*65fba592SSimon Glass ret = fdtdec_parse_phandle_with_args(blob, node, "pwms", "#pwm-cells", 83*65fba592SSimon Glass 0, 0, &args); 84*65fba592SSimon Glass if (ret) { 85*65fba592SSimon Glass debug("%s: Cannot get PWM phandle: ret=%d\n", __func__, ret); 86*65fba592SSimon Glass return ret; 87*65fba592SSimon Glass } 88*65fba592SSimon Glass 89*65fba592SSimon Glass ret = uclass_get_device_by_of_offset(UCLASS_PWM, args.node, &priv->pwm); 90*65fba592SSimon Glass if (ret) { 91*65fba592SSimon Glass debug("%s: Cannot get PWM: ret=%d\n", __func__, ret); 92*65fba592SSimon Glass return ret; 93*65fba592SSimon Glass } 94*65fba592SSimon Glass priv->channel = args.args[0]; 95*65fba592SSimon Glass priv->period_ns = args.args[1]; 96*65fba592SSimon Glass 97*65fba592SSimon Glass index = fdtdec_get_int(blob, node, "default-brightness-level", 255); 98*65fba592SSimon Glass cell = fdt_getprop(blob, node, "brightness-levels", &len); 99*65fba592SSimon Glass count = len / sizeof(u32); 100*65fba592SSimon Glass if (cell && count > index) { 101*65fba592SSimon Glass priv->default_level = fdt32_to_cpu(cell[index]); 102*65fba592SSimon Glass priv->max_level = fdt32_to_cpu(cell[count - 1]); 103*65fba592SSimon Glass } else { 104*65fba592SSimon Glass priv->default_level = index; 105*65fba592SSimon Glass priv->max_level = 255; 106*65fba592SSimon Glass } 107*65fba592SSimon Glass 108*65fba592SSimon Glass 109*65fba592SSimon Glass return 0; 110*65fba592SSimon Glass } 111*65fba592SSimon Glass 112*65fba592SSimon Glass static int pwm_backlight_probe(struct udevice *dev) 113*65fba592SSimon Glass { 114*65fba592SSimon Glass return 0; 115*65fba592SSimon Glass } 116*65fba592SSimon Glass 117*65fba592SSimon Glass static const struct backlight_ops pwm_backlight_ops = { 118*65fba592SSimon Glass .enable = pwm_backlight_enable, 119*65fba592SSimon Glass }; 120*65fba592SSimon Glass 121*65fba592SSimon Glass static const struct udevice_id pwm_backlight_ids[] = { 122*65fba592SSimon Glass { .compatible = "pwm-backlight" }, 123*65fba592SSimon Glass { } 124*65fba592SSimon Glass }; 125*65fba592SSimon Glass 126*65fba592SSimon Glass U_BOOT_DRIVER(pwm_backlight) = { 127*65fba592SSimon Glass .name = "pwm_backlight", 128*65fba592SSimon Glass .id = UCLASS_PANEL_BACKLIGHT, 129*65fba592SSimon Glass .of_match = pwm_backlight_ids, 130*65fba592SSimon Glass .ops = &pwm_backlight_ops, 131*65fba592SSimon Glass .ofdata_to_platdata = pwm_backlight_ofdata_to_platdata, 132*65fba592SSimon Glass .probe = pwm_backlight_probe, 133*65fba592SSimon Glass .priv_auto_alloc_size = sizeof(struct pwm_backlight_priv), 134*65fba592SSimon Glass }; 135