drivers/gpio/gpio-latch.c

1 // SPDX-License-Identifier: GPL-2.0
10  * CLK0 ----------------------.        ,--------.
11  * CLK1 -------------------.  `--------|>    #0 |
13  * OUT0 ----------------+--|-----------|D0    Q0|-----|<
14  * OUT1 --------------+-|--|-----------|D1    Q1|-----|<
15  * OUT2 ------------+-|-|--|-----------|D2    Q2|-----|<
16  * OUT3 ----------+-|-|-|--|-----------|D3    Q3|-----|<
17  * OUT4 --------+-|-|-|-|--|-----------|D4    Q4|-----|<
18  * OUT5 ------+-|-|-|-|-|--|-----------|D5    Q5|-----|<
19  * OUT6 ----+-|-|-|-|-|-|--|-----------|D6    Q6|-----|<
20  * OUT7 --+-|-|-|-|-|-|-|--|-----------|D7    Q7|-----|<
21  *        | | | | | | | |  |           `--------'
23  *        | | | | | | | |  |           ,--------.
24  *        | | | | | | | |  `-----------|>    #1 |
26  *        | | | | | | | `--------------|D0    Q0|-----|<
27  *        | | | | | | `----------------|D1    Q1|-----|<
28  *        | | | | | `------------------|D2    Q2|-----|<
29  *        | | | | `--------------------|D3    Q3|-----|<
30  *        | | | `----------------------|D4    Q4|-----|<
31  *        | | `------------------------|D5    Q5|-----|<
32  *        | `--------------------------|D6    Q6|-----|<
33  *        `----------------------------|D7    Q7|-----|<
34  *                                     `--------'
78 	int latch = offset / priv->n_latched_gpios;  in gpio_latch_set_unlocked()
81 	assign_bit(offset, priv->shadow, val);  in gpio_latch_set_unlocked()
83 	for (i = 0; i < priv->n_latched_gpios; i++)  in gpio_latch_set_unlocked()
84 		set(priv->latched_gpios->desc[i],  in gpio_latch_set_unlocked()
85 		    test_bit(latch * priv->n_latched_gpios + i, priv->shadow));  in gpio_latch_set_unlocked()
87 	ndelay(priv->setup_duration_ns);  in gpio_latch_set_unlocked()
88 	set(priv->clk_gpios->desc[latch], 1);  in gpio_latch_set_unlocked()
89 	ndelay(priv->clock_duration_ns);  in gpio_latch_set_unlocked()
90 	set(priv->clk_gpios->desc[latch], 0);  in gpio_latch_set_unlocked()
98 	spin_lock_irqsave(&priv->spinlock, flags);  in gpio_latch_set()
102 	spin_unlock_irqrestore(&priv->spinlock, flags);  in gpio_latch_set()
109 	mutex_lock(&priv->mutex);  in gpio_latch_set_can_sleep()
113 	mutex_unlock(&priv->mutex);  in gpio_latch_set_can_sleep()
121 		if (gpiod_cansleep(priv->clk_gpios->desc[i]))  in gpio_latch_can_sleep()
124 	for (i = 0; i < priv->n_latched_gpios; i++)  in gpio_latch_can_sleep()
125 		if (gpiod_cansleep(priv->latched_gpios->desc[i]))  in gpio_latch_can_sleep()
143 	struct device_node *np = pdev->dev.of_node;  in gpio_latch_probe()
145 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);  in gpio_latch_probe()
147 		return -ENOMEM;  in gpio_latch_probe()
149 	priv->clk_gpios = devm_gpiod_get_array(&pdev->dev, "clk", GPIOD_OUT_LOW);  in gpio_latch_probe()
150 	if (IS_ERR(priv->clk_gpios))  in gpio_latch_probe()
151 		return PTR_ERR(priv->clk_gpios);  in gpio_latch_probe()
153 	priv->latched_gpios = devm_gpiod_get_array(&pdev->dev, "latched", GPIOD_OUT_LOW);  in gpio_latch_probe()
154 	if (IS_ERR(priv->latched_gpios))  in gpio_latch_probe()
155 		return PTR_ERR(priv->latched_gpios);  in gpio_latch_probe()
157 	n_latches = priv->clk_gpios->ndescs;  in gpio_latch_probe()
158 	priv->n_latched_gpios = priv->latched_gpios->ndescs;  in gpio_latch_probe()
160 	priv->shadow = devm_bitmap_zalloc(&pdev->dev, n_latches * priv->n_latched_gpios,  in gpio_latch_probe()
162 	if (!priv->shadow)  in gpio_latch_probe()
163 		return -ENOMEM;  in gpio_latch_probe()
166 		priv->gc.can_sleep = true;  in gpio_latch_probe()
167 		priv->gc.set = gpio_latch_set_can_sleep;  in gpio_latch_probe()
168 		mutex_init(&priv->mutex);  in gpio_latch_probe()
170 		priv->gc.can_sleep = false;  in gpio_latch_probe()
171 		priv->gc.set = gpio_latch_set;  in gpio_latch_probe()
172 		spin_lock_init(&priv->spinlock);  in gpio_latch_probe()
175 	of_property_read_u32(np, "setup-duration-ns", &priv->setup_duration_ns);  in gpio_latch_probe()
176 	if (priv->setup_duration_ns > DURATION_NS_MAX) {  in gpio_latch_probe()
177 		dev_warn(&pdev->dev, "setup-duration-ns too high, limit to %d\n",  in gpio_latch_probe()
179 		priv->setup_duration_ns = DURATION_NS_MAX;  in gpio_latch_probe()
182 	of_property_read_u32(np, "clock-duration-ns", &priv->clock_duration_ns);  in gpio_latch_probe()
183 	if (priv->clock_duration_ns > DURATION_NS_MAX) {  in gpio_latch_probe()
184 		dev_warn(&pdev->dev, "clock-duration-ns too high, limit to %d\n",  in gpio_latch_probe()
186 		priv->clock_duration_ns = DURATION_NS_MAX;  in gpio_latch_probe()
189 	priv->gc.get_direction = gpio_latch_get_direction;  in gpio_latch_probe()
190 	priv->gc.ngpio = n_latches * priv->n_latched_gpios;  in gpio_latch_probe()
191 	priv->gc.owner = THIS_MODULE;  in gpio_latch_probe()
192 	priv->gc.base = -1;  in gpio_latch_probe()
193 	priv->gc.parent = &pdev->dev;  in gpio_latch_probe()
197 	return devm_gpiochip_add_data(&pdev->dev, &priv->gc, priv);  in gpio_latch_probe()
202 		.compatible = "gpio-latch",
210 		.name		= "gpio-latch",