1 // SPDX-License-Identifier: GPL-2.0
9 #include <linux/spi/spi.h>
13  *  CR0014114 SPI protocol descrtiption:
14  *  +----+-----------------------------------+----+
15  *  | CMD|             BRIGHTNESS            |CRC |
16  *  +----+-----------------------------------+----+
18  *  |    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+    |
20  *  | 1  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1  |
22  *  |    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+    |
24  *  +----+-----------------------------------+----+
26  *  +---------------------------------------------+
29  *      SPI -> board0 -> board1 -> board2 ..
32 /* CR0014114 SPI commands */
56 	struct spi_device	*spi;  member
65 	u8	crc;  in cr0014114_calc_crc()  local
67 	for (i = 1, crc = 1; i < len - 1; i++)  in cr0014114_calc_crc()
68 		crc += buf[i];  in cr0014114_calc_crc()
69 	crc |= BIT(7);  in cr0014114_calc_crc()
71 	/* special case when CRC matches the SPI commands */  in cr0014114_calc_crc()
72 	if (crc == CR_SET_BRIGHTNESS ||  in cr0014114_calc_crc()
73 	    crc == CR_INIT_REENUMERATE ||  in cr0014114_calc_crc()
74 	    crc == CR_NEXT_REENUMERATE)  in cr0014114_calc_crc()
75 		crc = 0xfe;  in cr0014114_calc_crc()
77 	buf[len - 1] = crc;  in cr0014114_calc_crc()
86 	dev_dbg(priv->dev, "LEDs recount is started\n");  in cr0014114_recount()
89 	ret = spi_write(priv->spi, &cmd, sizeof(cmd));  in cr0014114_recount()
94 	for (i = 0; i < priv->count; i++) {  in cr0014114_recount()
97 		ret = spi_write(priv->spi, &cmd, sizeof(cmd));  in cr0014114_recount()
103 	dev_dbg(priv->dev, "LEDs recount is finished\n");  in cr0014114_recount()
106 		dev_err(priv->dev, "with error %d", ret);  in cr0014114_recount()
117 	/* to avoid SPI mistiming with firmware we should wait some time */  in cr0014114_sync()
118 	if (time_after(priv->delay, now)) {  in cr0014114_sync()
119 		udelay = jiffies_to_usecs(priv->delay - now);  in cr0014114_sync()
123 	if (unlikely(priv->do_recount)) {  in cr0014114_sync()
128 		priv->do_recount = false;  in cr0014114_sync()
132 	priv->buf[0] = CR_SET_BRIGHTNESS;  in cr0014114_sync()
133 	for (i = 0; i < priv->count; i++)  in cr0014114_sync()
134 		priv->buf[i + 1] = priv->leds[i].brightness;  in cr0014114_sync()
135 	cr0014114_calc_crc(priv->buf, priv->count + 2);  in cr0014114_sync()
136 	ret = spi_write(priv->spi, priv->buf, priv->count + 2);  in cr0014114_sync()
139 	priv->delay = jiffies + msecs_to_jiffies(CR_FW_DELAY_MSEC);  in cr0014114_sync()
151 	mutex_lock(&priv->lock);  in cr0014114_recount_work()
152 	priv->do_recount = true;  in cr0014114_recount_work()
154 	mutex_unlock(&priv->lock);  in cr0014114_recount_work()
157 		dev_warn(priv->dev, "sync of LEDs failed %d\n", ret);  in cr0014114_recount_work()
159 	schedule_delayed_work(&priv->work, CR_RECOUNT_DELAY);  in cr0014114_recount_work()
170 	dev_dbg(led->priv->dev, "Set brightness to %d\n", brightness);  in cr0014114_set_sync()
172 	mutex_lock(&led->priv->lock);  in cr0014114_set_sync()
173 	led->brightness = (u8)brightness;  in cr0014114_set_sync()
174 	ret = cr0014114_sync(led->priv);  in cr0014114_set_sync()
175 	mutex_unlock(&led->priv->lock);  in cr0014114_set_sync()
188 	device_for_each_child_node(priv->dev, child) {  in cr0014114_probe_dt()
189 		led = &priv->leds[i];  in cr0014114_probe_dt()
191 		led->priv			  = priv;  in cr0014114_probe_dt()
192 		led->ldev.max_brightness	  = CR_MAX_BRIGHTNESS;  in cr0014114_probe_dt()
193 		led->ldev.brightness_set_blocking = cr0014114_set_sync;  in cr0014114_probe_dt()
199 		ret = devm_led_classdev_register_ext(priv->dev, &led->ldev,  in cr0014114_probe_dt()
202 			dev_err(priv->dev,  in cr0014114_probe_dt()
214 static int cr0014114_probe(struct spi_device *spi)  in cr0014114_probe()  argument
220 	count = device_get_child_node_count(&spi->dev);  in cr0014114_probe()
222 		dev_err(&spi->dev, "LEDs are not defined in device tree!");  in cr0014114_probe()
223 		return -ENODEV;  in cr0014114_probe()
226 	priv = devm_kzalloc(&spi->dev, struct_size(priv, leds, count),  in cr0014114_probe()
229 		return -ENOMEM;  in cr0014114_probe()
231 	priv->buf = devm_kzalloc(&spi->dev, count + 2, GFP_KERNEL);  in cr0014114_probe()
232 	if (!priv->buf)  in cr0014114_probe()
233 		return -ENOMEM;  in cr0014114_probe()
235 	mutex_init(&priv->lock);  in cr0014114_probe()
236 	INIT_DELAYED_WORK(&priv->work, cr0014114_recount_work);  in cr0014114_probe()
237 	priv->count	= count;  in cr0014114_probe()
238 	priv->dev	= &spi->dev;  in cr0014114_probe()
239 	priv->spi	= spi;  in cr0014114_probe()
240 	priv->delay	= jiffies -  in cr0014114_probe()
243 	priv->do_recount = true;  in cr0014114_probe()
246 		dev_err(priv->dev, "first recount failed %d\n", ret);  in cr0014114_probe()
250 	priv->do_recount = true;  in cr0014114_probe()
253 		dev_err(priv->dev, "second recount failed %d\n", ret);  in cr0014114_probe()
262 	schedule_delayed_work(&priv->work, CR_RECOUNT_DELAY);  in cr0014114_probe()
264 	spi_set_drvdata(spi, priv);  in cr0014114_probe()
269 static void cr0014114_remove(struct spi_device *spi)  in cr0014114_remove()  argument
271 	struct cr0014114 *priv = spi_get_drvdata(spi);  in cr0014114_remove()
273 	cancel_delayed_work_sync(&priv->work);  in cr0014114_remove()
274 	mutex_destroy(&priv->lock);  in cr0014114_remove()
298 MODULE_ALIAS("spi:cr0014114");