1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Backlight driver for Marvell Semiconductor 88PM8606 4 * 5 * Copyright (C) 2009 Marvell International Ltd. 6 * Haojian Zhuang <haojian.zhuang@marvell.com> 7 */ 8 9 #include <linux/init.h> 10 #include <linux/kernel.h> 11 #include <linux/of.h> 12 #include <linux/platform_device.h> 13 #include <linux/slab.h> 14 #include <linux/fb.h> 15 #include <linux/i2c.h> 16 #include <linux/backlight.h> 17 #include <linux/mfd/88pm860x.h> 18 #include <linux/module.h> 19 20 #define MAX_BRIGHTNESS (0xFF) 21 #define MIN_BRIGHTNESS (0) 22 23 #define CURRENT_BITMASK (0x1F << 1) 24 25 struct pm860x_backlight_data { 26 struct pm860x_chip *chip; 27 struct i2c_client *i2c; 28 int current_brightness; 29 int port; 30 int pwm; 31 int iset; 32 int reg_duty_cycle; 33 int reg_always_on; 34 int reg_current; 35 }; 36 37 static int backlight_power_set(struct pm860x_chip *chip, int port, 38 int on) 39 { 40 int ret = -EINVAL; 41 42 switch (port) { 43 case 0: 44 ret = on ? pm8606_osc_enable(chip, WLED1_DUTY) : 45 pm8606_osc_disable(chip, WLED1_DUTY); 46 break; 47 case 1: 48 ret = on ? pm8606_osc_enable(chip, WLED2_DUTY) : 49 pm8606_osc_disable(chip, WLED2_DUTY); 50 break; 51 case 2: 52 ret = on ? pm8606_osc_enable(chip, WLED3_DUTY) : 53 pm8606_osc_disable(chip, WLED3_DUTY); 54 break; 55 } 56 return ret; 57 } 58 59 static int pm860x_backlight_set(struct backlight_device *bl, int brightness) 60 { 61 struct pm860x_backlight_data *data = bl_get_data(bl); 62 struct pm860x_chip *chip = data->chip; 63 unsigned char value; 64 int ret; 65 66 if (brightness > MAX_BRIGHTNESS) 67 value = MAX_BRIGHTNESS; 68 else 69 value = brightness; 70 71 if (brightness) 72 backlight_power_set(chip, data->port, 1); 73 74 ret = pm860x_reg_write(data->i2c, data->reg_duty_cycle, value); 75 if (ret < 0) 76 goto out; 77 78 if ((data->current_brightness == 0) && brightness) { 79 if (data->iset) { 80 ret = pm860x_set_bits(data->i2c, data->reg_current, 81 CURRENT_BITMASK, data->iset); 82 if (ret < 0) 83 goto out; 84 } 85 if (data->pwm) { 86 ret = pm860x_set_bits(data->i2c, PM8606_PWM, 87 PM8606_PWM_FREQ_MASK, data->pwm); 88 if (ret < 0) 89 goto out; 90 } 91 if (brightness == MAX_BRIGHTNESS) { 92 /* set WLED_ON bit as 100% */ 93 ret = pm860x_set_bits(data->i2c, data->reg_always_on, 94 PM8606_WLED_ON, PM8606_WLED_ON); 95 } 96 } else { 97 if (brightness == MAX_BRIGHTNESS) { 98 /* set WLED_ON bit as 100% */ 99 ret = pm860x_set_bits(data->i2c, data->reg_always_on, 100 PM8606_WLED_ON, PM8606_WLED_ON); 101 } else { 102 /* clear WLED_ON bit since it's not 100% */ 103 ret = pm860x_set_bits(data->i2c, data->reg_always_on, 104 PM8606_WLED_ON, 0); 105 } 106 } 107 if (ret < 0) 108 goto out; 109 110 if (brightness == 0) 111 backlight_power_set(chip, data->port, 0); 112 113 dev_dbg(chip->dev, "set brightness %d\n", value); 114 data->current_brightness = value; 115 return 0; 116 out: 117 dev_dbg(chip->dev, "set brightness %d failure with return value: %d\n", 118 value, ret); 119 return ret; 120 } 121 122 static int pm860x_backlight_update_status(struct backlight_device *bl) 123 { 124 return pm860x_backlight_set(bl, backlight_get_brightness(bl)); 125 } 126 127 static int pm860x_backlight_get_brightness(struct backlight_device *bl) 128 { 129 struct pm860x_backlight_data *data = bl_get_data(bl); 130 struct pm860x_chip *chip = data->chip; 131 int ret; 132 133 ret = pm860x_reg_read(data->i2c, data->reg_duty_cycle); 134 if (ret < 0) 135 goto out; 136 data->current_brightness = ret; 137 dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness); 138 return data->current_brightness; 139 out: 140 return -EINVAL; 141 } 142 143 static const struct backlight_ops pm860x_backlight_ops = { 144 .options = BL_CORE_SUSPENDRESUME, 145 .update_status = pm860x_backlight_update_status, 146 .get_brightness = pm860x_backlight_get_brightness, 147 }; 148 149 #ifdef CONFIG_OF 150 static int pm860x_backlight_dt_init(struct platform_device *pdev, 151 struct pm860x_backlight_data *data, 152 char *name) 153 { 154 struct device_node *nproot, *np; 155 int iset = 0; 156 157 nproot = of_get_child_by_name(pdev->dev.parent->of_node, "backlights"); 158 if (!nproot) { 159 dev_err(&pdev->dev, "failed to find backlights node\n"); 160 return -ENODEV; 161 } 162 for_each_child_of_node(nproot, np) { 163 if (of_node_name_eq(np, name)) { 164 of_property_read_u32(np, "marvell,88pm860x-iset", 165 &iset); 166 data->iset = PM8606_WLED_CURRENT(iset); 167 of_property_read_u32(np, "marvell,88pm860x-pwm", 168 &data->pwm); 169 of_node_put(np); 170 break; 171 } 172 } 173 of_node_put(nproot); 174 return 0; 175 } 176 #else 177 #define pm860x_backlight_dt_init(x, y, z) (-1) 178 #endif 179 180 static int pm860x_backlight_probe(struct platform_device *pdev) 181 { 182 struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent); 183 struct pm860x_backlight_pdata *pdata = dev_get_platdata(&pdev->dev); 184 struct pm860x_backlight_data *data; 185 struct backlight_device *bl; 186 struct resource *res; 187 struct backlight_properties props; 188 char name[MFD_NAME_SIZE]; 189 int ret = 0; 190 191 data = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_backlight_data), 192 GFP_KERNEL); 193 if (data == NULL) 194 return -ENOMEM; 195 res = platform_get_resource_byname(pdev, IORESOURCE_REG, "duty cycle"); 196 if (!res) { 197 dev_err(&pdev->dev, "No REG resource for duty cycle\n"); 198 return -ENXIO; 199 } 200 data->reg_duty_cycle = res->start; 201 res = platform_get_resource_byname(pdev, IORESOURCE_REG, "always on"); 202 if (!res) { 203 dev_err(&pdev->dev, "No REG resource for always on\n"); 204 return -ENXIO; 205 } 206 data->reg_always_on = res->start; 207 res = platform_get_resource_byname(pdev, IORESOURCE_REG, "current"); 208 if (!res) { 209 dev_err(&pdev->dev, "No REG resource for current\n"); 210 return -ENXIO; 211 } 212 data->reg_current = res->start; 213 214 memset(name, 0, MFD_NAME_SIZE); 215 sprintf(name, "backlight-%d", pdev->id); 216 data->port = pdev->id; 217 data->chip = chip; 218 data->i2c = (chip->id == CHIP_PM8606) ? chip->client : chip->companion; 219 data->current_brightness = MAX_BRIGHTNESS; 220 if (pm860x_backlight_dt_init(pdev, data, name)) { 221 if (pdata) { 222 data->pwm = pdata->pwm; 223 data->iset = pdata->iset; 224 } 225 } 226 227 memset(&props, 0, sizeof(struct backlight_properties)); 228 props.type = BACKLIGHT_RAW; 229 props.max_brightness = MAX_BRIGHTNESS; 230 bl = devm_backlight_device_register(&pdev->dev, name, &pdev->dev, data, 231 &pm860x_backlight_ops, &props); 232 if (IS_ERR(bl)) { 233 dev_err(&pdev->dev, "failed to register backlight\n"); 234 return PTR_ERR(bl); 235 } 236 bl->props.brightness = MAX_BRIGHTNESS; 237 238 platform_set_drvdata(pdev, bl); 239 240 /* read current backlight */ 241 ret = pm860x_backlight_get_brightness(bl); 242 if (ret < 0) 243 return ret; 244 245 backlight_update_status(bl); 246 return 0; 247 } 248 249 static struct platform_driver pm860x_backlight_driver = { 250 .driver = { 251 .name = "88pm860x-backlight", 252 }, 253 .probe = pm860x_backlight_probe, 254 }; 255 256 module_platform_driver(pm860x_backlight_driver); 257 258 MODULE_DESCRIPTION("Backlight Driver for Marvell Semiconductor 88PM8606"); 259 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>"); 260 MODULE_LICENSE("GPL"); 261 MODULE_ALIAS("platform:88pm860x-backlight"); 262