1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * Driver for BCM6358 memory-mapped LEDs, based on leds-syscon.c |
4 | * |
5 | * Copyright 2015 Álvaro Fernández Rojas <noltari@gmail.com> |
6 | */ |
7 | #include <linux/delay.h> |
8 | #include <linux/io.h> |
9 | #include <linux/leds.h> |
10 | #include <linux/module.h> |
11 | #include <linux/of.h> |
12 | #include <linux/platform_device.h> |
13 | #include <linux/spinlock.h> |
14 | |
15 | #define BCM6358_REG_MODE 0x0 |
16 | #define BCM6358_REG_CTRL 0x4 |
17 | |
18 | #define BCM6358_SLED_CLKDIV_MASK 3 |
19 | #define BCM6358_SLED_CLKDIV_1 0 |
20 | #define BCM6358_SLED_CLKDIV_2 1 |
21 | #define BCM6358_SLED_CLKDIV_4 2 |
22 | #define BCM6358_SLED_CLKDIV_8 3 |
23 | |
24 | #define BCM6358_SLED_POLARITY BIT(2) |
25 | #define BCM6358_SLED_BUSY BIT(3) |
26 | |
27 | #define BCM6358_SLED_MAX_COUNT 32 |
28 | #define BCM6358_SLED_WAIT 100 |
29 | |
30 | /** |
31 | * struct bcm6358_led - state container for bcm6358 based LEDs |
32 | * @cdev: LED class device for this LED |
33 | * @mem: memory resource |
34 | * @lock: memory lock |
35 | * @pin: LED pin number |
36 | * @active_low: LED is active low |
37 | */ |
38 | struct bcm6358_led { |
39 | struct led_classdev cdev; |
40 | void __iomem *mem; |
41 | spinlock_t *lock; |
42 | unsigned long pin; |
43 | bool active_low; |
44 | }; |
45 | |
46 | static void bcm6358_led_write(void __iomem *reg, unsigned long data) |
47 | { |
48 | #ifdef CONFIG_CPU_BIG_ENDIAN |
49 | iowrite32be(data, reg); |
50 | #else |
51 | writel(val: data, addr: reg); |
52 | #endif |
53 | } |
54 | |
55 | static unsigned long bcm6358_led_read(void __iomem *reg) |
56 | { |
57 | #ifdef CONFIG_CPU_BIG_ENDIAN |
58 | return ioread32be(reg); |
59 | #else |
60 | return readl(addr: reg); |
61 | #endif |
62 | } |
63 | |
64 | static unsigned long bcm6358_led_busy(void __iomem *mem) |
65 | { |
66 | unsigned long val; |
67 | |
68 | while ((val = bcm6358_led_read(reg: mem + BCM6358_REG_CTRL)) & |
69 | BCM6358_SLED_BUSY) |
70 | udelay(BCM6358_SLED_WAIT); |
71 | |
72 | return val; |
73 | } |
74 | |
75 | static void bcm6358_led_set(struct led_classdev *led_cdev, |
76 | enum led_brightness value) |
77 | { |
78 | struct bcm6358_led *led = |
79 | container_of(led_cdev, struct bcm6358_led, cdev); |
80 | unsigned long flags, val; |
81 | |
82 | spin_lock_irqsave(led->lock, flags); |
83 | bcm6358_led_busy(mem: led->mem); |
84 | val = bcm6358_led_read(reg: led->mem + BCM6358_REG_MODE); |
85 | if ((led->active_low && value == LED_OFF) || |
86 | (!led->active_low && value != LED_OFF)) |
87 | val |= BIT(led->pin); |
88 | else |
89 | val &= ~(BIT(led->pin)); |
90 | bcm6358_led_write(reg: led->mem + BCM6358_REG_MODE, data: val); |
91 | spin_unlock_irqrestore(lock: led->lock, flags); |
92 | } |
93 | |
94 | static int bcm6358_led(struct device *dev, struct device_node *nc, u32 reg, |
95 | void __iomem *mem, spinlock_t *lock) |
96 | { |
97 | struct led_init_data init_data = {}; |
98 | struct bcm6358_led *led; |
99 | enum led_default_state state; |
100 | unsigned long val; |
101 | int rc; |
102 | |
103 | led = devm_kzalloc(dev, size: sizeof(*led), GFP_KERNEL); |
104 | if (!led) |
105 | return -ENOMEM; |
106 | |
107 | led->pin = reg; |
108 | led->mem = mem; |
109 | led->lock = lock; |
110 | |
111 | if (of_property_read_bool(np: nc, propname: "active-low" )) |
112 | led->active_low = true; |
113 | |
114 | init_data.fwnode = of_fwnode_handle(nc); |
115 | |
116 | state = led_init_default_state_get(fwnode: init_data.fwnode); |
117 | switch (state) { |
118 | case LEDS_DEFSTATE_ON: |
119 | led->cdev.brightness = LED_FULL; |
120 | break; |
121 | case LEDS_DEFSTATE_KEEP: |
122 | val = bcm6358_led_read(reg: led->mem + BCM6358_REG_MODE); |
123 | val &= BIT(led->pin); |
124 | if ((led->active_low && !val) || (!led->active_low && val)) |
125 | led->cdev.brightness = LED_FULL; |
126 | else |
127 | led->cdev.brightness = LED_OFF; |
128 | break; |
129 | default: |
130 | led->cdev.brightness = LED_OFF; |
131 | } |
132 | |
133 | bcm6358_led_set(led_cdev: &led->cdev, value: led->cdev.brightness); |
134 | |
135 | led->cdev.brightness_set = bcm6358_led_set; |
136 | |
137 | rc = devm_led_classdev_register_ext(parent: dev, led_cdev: &led->cdev, init_data: &init_data); |
138 | if (rc < 0) |
139 | return rc; |
140 | |
141 | dev_dbg(dev, "registered LED %s\n" , led->cdev.name); |
142 | |
143 | return 0; |
144 | } |
145 | |
146 | static int bcm6358_leds_probe(struct platform_device *pdev) |
147 | { |
148 | struct device *dev = &pdev->dev; |
149 | struct device_node *np = dev_of_node(dev: &pdev->dev); |
150 | struct device_node *child; |
151 | void __iomem *mem; |
152 | spinlock_t *lock; /* memory lock */ |
153 | unsigned long val; |
154 | u32 clk_div; |
155 | |
156 | mem = devm_platform_ioremap_resource(pdev, index: 0); |
157 | if (IS_ERR(ptr: mem)) |
158 | return PTR_ERR(ptr: mem); |
159 | |
160 | lock = devm_kzalloc(dev, size: sizeof(*lock), GFP_KERNEL); |
161 | if (!lock) |
162 | return -ENOMEM; |
163 | |
164 | spin_lock_init(lock); |
165 | |
166 | val = bcm6358_led_busy(mem); |
167 | val &= ~(BCM6358_SLED_POLARITY | BCM6358_SLED_CLKDIV_MASK); |
168 | if (of_property_read_bool(np, propname: "brcm,clk-dat-low" )) |
169 | val |= BCM6358_SLED_POLARITY; |
170 | of_property_read_u32(np, propname: "brcm,clk-div" , out_value: &clk_div); |
171 | switch (clk_div) { |
172 | case 8: |
173 | val |= BCM6358_SLED_CLKDIV_8; |
174 | break; |
175 | case 4: |
176 | val |= BCM6358_SLED_CLKDIV_4; |
177 | break; |
178 | case 2: |
179 | val |= BCM6358_SLED_CLKDIV_2; |
180 | break; |
181 | default: |
182 | val |= BCM6358_SLED_CLKDIV_1; |
183 | break; |
184 | } |
185 | bcm6358_led_write(reg: mem + BCM6358_REG_CTRL, data: val); |
186 | |
187 | for_each_available_child_of_node(np, child) { |
188 | int rc; |
189 | u32 reg; |
190 | |
191 | if (of_property_read_u32(np: child, propname: "reg" , out_value: ®)) |
192 | continue; |
193 | |
194 | if (reg >= BCM6358_SLED_MAX_COUNT) { |
195 | dev_err(dev, "invalid LED (%u >= %d)\n" , reg, |
196 | BCM6358_SLED_MAX_COUNT); |
197 | continue; |
198 | } |
199 | |
200 | rc = bcm6358_led(dev, nc: child, reg, mem, lock); |
201 | if (rc < 0) { |
202 | of_node_put(node: child); |
203 | return rc; |
204 | } |
205 | } |
206 | |
207 | return 0; |
208 | } |
209 | |
210 | static const struct of_device_id bcm6358_leds_of_match[] = { |
211 | { .compatible = "brcm,bcm6358-leds" , }, |
212 | { }, |
213 | }; |
214 | MODULE_DEVICE_TABLE(of, bcm6358_leds_of_match); |
215 | |
216 | static struct platform_driver bcm6358_leds_driver = { |
217 | .probe = bcm6358_leds_probe, |
218 | .driver = { |
219 | .name = "leds-bcm6358" , |
220 | .of_match_table = bcm6358_leds_of_match, |
221 | }, |
222 | }; |
223 | |
224 | module_platform_driver(bcm6358_leds_driver); |
225 | |
226 | MODULE_AUTHOR("Álvaro Fernández Rojas <noltari@gmail.com>" ); |
227 | MODULE_DESCRIPTION("LED driver for BCM6358 controllers" ); |
228 | MODULE_LICENSE("GPL v2" ); |
229 | MODULE_ALIAS("platform:leds-bcm6358" ); |
230 | |