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 int brightness = bl->props.brightness; 125 126 if (bl->props.power != FB_BLANK_UNBLANK) 127 brightness = 0; 128 129 if (bl->props.fb_blank != FB_BLANK_UNBLANK) 130 brightness = 0; 131 132 if (bl->props.state & BL_CORE_SUSPENDED) 133 brightness = 0; 134 135 return pm860x_backlight_set(bl, brightness); 136 } 137 138 static int pm860x_backlight_get_brightness(struct backlight_device *bl) 139 { 140 struct pm860x_backlight_data *data = bl_get_data(bl); 141 struct pm860x_chip *chip = data->chip; 142 int ret; 143 144 ret = pm860x_reg_read(data->i2c, data->reg_duty_cycle); 145 if (ret < 0) 146 goto out; 147 data->current_brightness = ret; 148 dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness); 149 return data->current_brightness; 150 out: 151 return -EINVAL; 152 } 153 154 static const struct backlight_ops pm860x_backlight_ops = { 155 .options = BL_CORE_SUSPENDRESUME, 156 .update_status = pm860x_backlight_update_status, 157 .get_brightness = pm860x_backlight_get_brightness, 158 }; 159 160 #ifdef CONFIG_OF 161 static int pm860x_backlight_dt_init(struct platform_device *pdev, 162 struct pm860x_backlight_data *data, 163 char *name) 164 { 165 struct device_node *nproot, *np; 166 int iset = 0; 167 168 nproot = of_get_child_by_name(pdev->dev.parent->of_node, "backlights"); 169 if (!nproot) { 170 dev_err(&pdev->dev, "failed to find backlights node\n"); 171 return -ENODEV; 172 } 173 for_each_child_of_node(nproot, np) { 174 if (of_node_name_eq(np, name)) { 175 of_property_read_u32(np, "marvell,88pm860x-iset", 176 &iset); 177 data->iset = PM8606_WLED_CURRENT(iset); 178 of_property_read_u32(np, "marvell,88pm860x-pwm", 179 &data->pwm); 180 of_node_put(np); 181 break; 182 } 183 } 184 of_node_put(nproot); 185 return 0; 186 } 187 #else 188 #define pm860x_backlight_dt_init(x, y, z) (-1) 189 #endif 190 191 static int pm860x_backlight_probe(struct platform_device *pdev) 192 { 193 struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent); 194 struct pm860x_backlight_pdata *pdata = dev_get_platdata(&pdev->dev); 195 struct pm860x_backlight_data *data; 196 struct backlight_device *bl; 197 struct resource *res; 198 struct backlight_properties props; 199 char name[MFD_NAME_SIZE]; 200 int ret = 0; 201 202 data = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_backlight_data), 203 GFP_KERNEL); 204 if (data == NULL) 205 return -ENOMEM; 206 res = platform_get_resource_byname(pdev, IORESOURCE_REG, "duty cycle"); 207 if (!res) { 208 dev_err(&pdev->dev, "No REG resource for duty cycle\n"); 209 return -ENXIO; 210 } 211 data->reg_duty_cycle = res->start; 212 res = platform_get_resource_byname(pdev, IORESOURCE_REG, "always on"); 213 if (!res) { 214 dev_err(&pdev->dev, "No REG resource for always on\n"); 215 return -ENXIO; 216 } 217 data->reg_always_on = res->start; 218 res = platform_get_resource_byname(pdev, IORESOURCE_REG, "current"); 219 if (!res) { 220 dev_err(&pdev->dev, "No REG resource for current\n"); 221 return -ENXIO; 222 } 223 data->reg_current = res->start; 224 225 memset(name, 0, MFD_NAME_SIZE); 226 sprintf(name, "backlight-%d", pdev->id); 227 data->port = pdev->id; 228 data->chip = chip; 229 data->i2c = (chip->id == CHIP_PM8606) ? chip->client : chip->companion; 230 data->current_brightness = MAX_BRIGHTNESS; 231 if (pm860x_backlight_dt_init(pdev, data, name)) { 232 if (pdata) { 233 data->pwm = pdata->pwm; 234 data->iset = pdata->iset; 235 } 236 } 237 238 memset(&props, 0, sizeof(struct backlight_properties)); 239 props.type = BACKLIGHT_RAW; 240 props.max_brightness = MAX_BRIGHTNESS; 241 bl = devm_backlight_device_register(&pdev->dev, name, &pdev->dev, data, 242 &pm860x_backlight_ops, &props); 243 if (IS_ERR(bl)) { 244 dev_err(&pdev->dev, "failed to register backlight\n"); 245 return PTR_ERR(bl); 246 } 247 bl->props.brightness = MAX_BRIGHTNESS; 248 249 platform_set_drvdata(pdev, bl); 250 251 /* read current backlight */ 252 ret = pm860x_backlight_get_brightness(bl); 253 if (ret < 0) 254 return ret; 255 256 backlight_update_status(bl); 257 return 0; 258 } 259 260 static struct platform_driver pm860x_backlight_driver = { 261 .driver = { 262 .name = "88pm860x-backlight", 263 }, 264 .probe = pm860x_backlight_probe, 265 }; 266 267 module_platform_driver(pm860x_backlight_driver); 268 269 MODULE_DESCRIPTION("Backlight Driver for Marvell Semiconductor 88PM8606"); 270 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>"); 271 MODULE_LICENSE("GPL"); 272 MODULE_ALIAS("platform:88pm860x-backlight"); 273