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/property.h> |
11 | |
12 | #include <linux/leds-ti-lmu-common.h> |
13 | |
14 | static const unsigned int ramp_table[16] = {2048, 262000, 524000, 1049000, |
15 | 2090000, 4194000, 8389000, 16780000, 33550000, |
16 | 41940000, 50330000, 58720000, 67110000, |
17 | 83880000, 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(map: regmap, reg, |
36 | LMU_11BIT_LSB_MASK, |
37 | val: 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(map: 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 unsigned 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 0; |
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(usec: lmu_bank->ramp_up_usec); |
94 | ramp_down = ti_lmu_common_convert_ramp_to_index(usec: lmu_bank->ramp_down_usec); |
95 | } |
96 | |
97 | ramp = (ramp_up << 4) | ramp_down; |
98 | |
99 | return regmap_write(map: regmap, reg: lmu_bank->runtime_ramp_reg, val: ramp); |
100 | |
101 | } |
102 | EXPORT_SYMBOL(ti_lmu_common_set_ramp); |
103 | |
104 | int ti_lmu_common_get_ramp_params(struct device *dev, |
105 | struct fwnode_handle *child, |
106 | struct ti_lmu_bank *lmu_data) |
107 | { |
108 | int ret; |
109 | |
110 | ret = fwnode_property_read_u32(fwnode: child, propname: "ramp-up-us" , |
111 | val: &lmu_data->ramp_up_usec); |
112 | if (ret) |
113 | dev_warn(dev, "ramp-up-us property missing\n" ); |
114 | |
115 | |
116 | ret = fwnode_property_read_u32(fwnode: child, propname: "ramp-down-us" , |
117 | val: &lmu_data->ramp_down_usec); |
118 | if (ret) |
119 | dev_warn(dev, "ramp-down-us property missing\n" ); |
120 | |
121 | return 0; |
122 | } |
123 | EXPORT_SYMBOL(ti_lmu_common_get_ramp_params); |
124 | |
125 | int ti_lmu_common_get_brt_res(struct device *dev, struct fwnode_handle *child, |
126 | struct ti_lmu_bank *lmu_data) |
127 | { |
128 | int ret; |
129 | |
130 | ret = device_property_read_u32(dev, propname: "ti,brightness-resolution" , |
131 | val: &lmu_data->max_brightness); |
132 | if (ret) |
133 | ret = fwnode_property_read_u32(fwnode: child, |
134 | propname: "ti,brightness-resolution" , |
135 | val: &lmu_data->max_brightness); |
136 | if (lmu_data->max_brightness <= 0) { |
137 | lmu_data->max_brightness = MAX_BRIGHTNESS_8BIT; |
138 | return ret; |
139 | } |
140 | |
141 | if (lmu_data->max_brightness > MAX_BRIGHTNESS_11BIT) |
142 | lmu_data->max_brightness = MAX_BRIGHTNESS_11BIT; |
143 | |
144 | |
145 | return 0; |
146 | } |
147 | EXPORT_SYMBOL(ti_lmu_common_get_brt_res); |
148 | |
149 | MODULE_DESCRIPTION("TI LMU common LED framework" ); |
150 | MODULE_AUTHOR("Sebastian Reichel" ); |
151 | MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>" ); |
152 | MODULE_LICENSE("GPL v2" ); |
153 | MODULE_ALIAS("ti-lmu-led-common" ); |
154 | |