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_dev: 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, port: data->port, on: 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, port: data->port, on: 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, brightness: backlight_get_brightness(bd: 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_dev: 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(node: pdev->dev.parent->of_node, name: "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, propname: "marvell,88pm860x-iset" , |
165 | out_value: &iset); |
166 | data->iset = PM8606_WLED_CURRENT(iset); |
167 | of_property_read_u32(np, propname: "marvell,88pm860x-pwm" , |
168 | out_value: &data->pwm); |
169 | of_node_put(node: np); |
170 | break; |
171 | } |
172 | } |
173 | of_node_put(node: 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(dev: pdev->dev.parent); |
183 | struct pm860x_backlight_pdata *pdata = dev_get_platdata(dev: &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(dev: &pdev->dev, size: 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(buf: name, fmt: "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(dev: &pdev->dev, name, parent: &pdev->dev, devdata: data, |
231 | ops: &pm860x_backlight_ops, props: &props); |
232 | if (IS_ERR(ptr: bl)) { |
233 | dev_err(&pdev->dev, "failed to register backlight\n" ); |
234 | return PTR_ERR(ptr: bl); |
235 | } |
236 | bl->props.brightness = MAX_BRIGHTNESS; |
237 | |
238 | platform_set_drvdata(pdev, data: 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(bd: 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 | |