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1 | // SPDX-License-Identifier: GPL-2.0 |
2 | // Copyright 2015 Texas Instruments | |
3 | // Copyright 2018 Sebastian Reichel | |
4 | // Copyright 2018 Pavel Machek <pavel@ucw.cz> | |
5 | // TI LMU LED common framework, based on previous work from | |
6 | // Milo Kim <milo.kim@ti.com> | |
7 | ||
8 | #include <linux/bitops.h> | |
9 | #include <linux/err.h> | |
10 | #include <linux/of_device.h> | |
11 | ||
12 | #include <linux/leds-ti-lmu-common.h> | |
13 | ||
14 | const static int ramp_table[16] = {2048, 262000, 524000, 1049000, 2090000, | |
15 | 4194000, 8389000, 16780000, 33550000, 41940000, | |
16 | 50330000, 58720000, 67110000, 83880000, | |
17 | 100660000, 117440000}; | |
18 | ||
19 | static int ti_lmu_common_update_brightness(struct ti_lmu_bank *lmu_bank, | |
20 | int brightness) | |
21 | { | |
22 | struct regmap *regmap = lmu_bank->regmap; | |
23 | u8 reg, val; | |
24 | int ret; | |
25 | ||
26 | /* | |
27 | * Brightness register update | |
28 | * | |
29 | * 11 bit dimming: update LSB bits and write MSB byte. | |
30 | * MSB brightness should be shifted. | |
31 | * 8 bit dimming: write MSB byte. | |
32 | */ | |
33 | if (lmu_bank->max_brightness == MAX_BRIGHTNESS_11BIT) { | |
34 | reg = lmu_bank->lsb_brightness_reg; | |
35 | ret = regmap_update_bits(regmap, reg, | |
36 | LMU_11BIT_LSB_MASK, | |
37 | brightness); | |
38 | if (ret) | |
39 | return ret; | |
40 | ||
41 | val = brightness >> LMU_11BIT_MSB_SHIFT; | |
42 | } else { | |
43 | val = brightness; | |
44 | } | |
45 | ||
46 | reg = lmu_bank->msb_brightness_reg; | |
47 | ||
48 | return regmap_write(regmap, reg, val); | |
49 | } | |
50 | ||
51 | int ti_lmu_common_set_brightness(struct ti_lmu_bank *lmu_bank, int brightness) | |
52 | { | |
53 | return ti_lmu_common_update_brightness(lmu_bank, brightness); | |
54 | } | |
55 | EXPORT_SYMBOL(ti_lmu_common_set_brightness); | |
56 | ||
57 | static int ti_lmu_common_convert_ramp_to_index(unsigned int usec) | |
58 | { | |
59 | int size = ARRAY_SIZE(ramp_table); | |
60 | int i; | |
61 | ||
62 | if (usec <= ramp_table[0]) | |
63 | return 0; | |
64 | ||
65 | if (usec > ramp_table[size - 1]) | |
66 | return size - 1; | |
67 | ||
68 | for (i = 1; i < size; i++) { | |
69 | if (usec == ramp_table[i]) | |
70 | return i; | |
71 | ||
72 | /* Find an approximate index by looking up the table */ | |
73 | if (usec > ramp_table[i - 1] && usec < ramp_table[i]) { | |
74 | if (usec - ramp_table[i - 1] < ramp_table[i] - usec) | |
75 | return i - 1; | |
76 | else | |
77 | return i; | |
78 | } | |
79 | } | |
80 | ||
81 | return -EINVAL; | |
82 | } | |
83 | ||
84 | int ti_lmu_common_set_ramp(struct ti_lmu_bank *lmu_bank) | |
85 | { | |
86 | struct regmap *regmap = lmu_bank->regmap; | |
87 | u8 ramp, ramp_up, ramp_down; | |
88 | ||
89 | if (lmu_bank->ramp_up_usec == 0 && lmu_bank->ramp_down_usec == 0) { | |
90 | ramp_up = 0; | |
91 | ramp_down = 0; | |
92 | } else { | |
93 | ramp_up = ti_lmu_common_convert_ramp_to_index(lmu_bank->ramp_up_usec); | |
94 | ramp_down = ti_lmu_common_convert_ramp_to_index(lmu_bank->ramp_down_usec); | |
95 | } | |
96 | ||
97 | if (ramp_up < 0 || ramp_down < 0) | |
98 | return -EINVAL; | |
99 | ||
100 | ramp = (ramp_up << 4) | ramp_down; | |
101 | ||
102 | return regmap_write(regmap, lmu_bank->runtime_ramp_reg, ramp); | |
103 | ||
104 | } | |
105 | EXPORT_SYMBOL(ti_lmu_common_set_ramp); | |
106 | ||
107 | int ti_lmu_common_get_ramp_params(struct device *dev, | |
108 | struct fwnode_handle *child, | |
109 | struct ti_lmu_bank *lmu_data) | |
110 | { | |
111 | int ret; | |
112 | ||
113 | ret = fwnode_property_read_u32(child, "ramp-up-us", | |
114 | &lmu_data->ramp_up_usec); | |
115 | if (ret) | |
116 | dev_warn(dev, "ramp-up-us property missing\n"); | |
117 | ||
118 | ||
119 | ret = fwnode_property_read_u32(child, "ramp-down-us", | |
120 | &lmu_data->ramp_down_usec); | |
121 | if (ret) | |
122 | dev_warn(dev, "ramp-down-us property missing\n"); | |
123 | ||
124 | return 0; | |
125 | } | |
126 | EXPORT_SYMBOL(ti_lmu_common_get_ramp_params); | |
127 | ||
128 | int ti_lmu_common_get_brt_res(struct device *dev, struct fwnode_handle *child, | |
129 | struct ti_lmu_bank *lmu_data) | |
130 | { | |
131 | int ret; | |
132 | ||
133 | ret = device_property_read_u32(dev, "ti,brightness-resolution", | |
134 | &lmu_data->max_brightness); | |
135 | if (ret) | |
136 | ret = fwnode_property_read_u32(child, | |
137 | "ti,brightness-resolution", | |
138 | &lmu_data->max_brightness); | |
139 | if (lmu_data->max_brightness <= 0) { | |
140 | lmu_data->max_brightness = MAX_BRIGHTNESS_8BIT; | |
141 | return ret; | |
142 | } | |
143 | ||
144 | if (lmu_data->max_brightness > MAX_BRIGHTNESS_11BIT) | |
145 | lmu_data->max_brightness = MAX_BRIGHTNESS_11BIT; | |
146 | ||
147 | ||
148 | return 0; | |
149 | } | |
150 | EXPORT_SYMBOL(ti_lmu_common_get_brt_res); | |
151 | ||
152 | MODULE_DESCRIPTION("TI LMU common LED framework"); | |
153 | MODULE_AUTHOR("Sebastian Reichel"); | |
154 | MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>"); | |
155 | MODULE_LICENSE("GPL v2"); | |
156 | MODULE_ALIAS("ti-lmu-led-common"); |