1 // SPDX-License-Identifier: GPL-2.0-only
25  * It provides control for spi chip select lines so that any chipselect
26  * (out of 4 possible chipselects in pl022) can be made low to select
31  * struct spear_spics - represents spi chip select control
36  * @cs_enable_mask: mask to select bits required to select chipselect
40  * @chip: gpio_chip abstraction
51 	struct gpio_chip	chip;  member
55 static int spics_get_value(struct gpio_chip *chip, unsigned offset)  in spics_get_value()  argument
57 	return -ENXIO;  in spics_get_value()
60 static void spics_set_value(struct gpio_chip *chip, unsigned offset, int value)  in spics_set_value()  argument
62 	struct spear_spics *spics = gpiochip_get_data(chip);  in spics_set_value()
65 	/* select chip select from register */  in spics_set_value()
66 	tmp = readl_relaxed(spics->base + spics->perip_cfg);  in spics_set_value()
67 	if (spics->last_off != offset) {  in spics_set_value()
68 		spics->last_off = offset;  in spics_set_value()
69 		tmp &= ~(spics->cs_enable_mask << spics->cs_enable_shift);  in spics_set_value()
70 		tmp |= offset << spics->cs_enable_shift;  in spics_set_value()
73 	/* toggle chip select line */  in spics_set_value()
74 	tmp &= ~(0x1 << spics->cs_value_bit);  in spics_set_value()
75 	tmp |= value << spics->cs_value_bit;  in spics_set_value()
76 	writel_relaxed(tmp, spics->base + spics->perip_cfg);  in spics_set_value()
79 static int spics_direction_input(struct gpio_chip *chip, unsigned offset)  in spics_direction_input()  argument
81 	return -ENXIO;  in spics_direction_input()
84 static int spics_direction_output(struct gpio_chip *chip, unsigned offset,  in spics_direction_output()  argument
87 	spics_set_value(chip, offset, value);  in spics_direction_output()
91 static int spics_request(struct gpio_chip *chip, unsigned offset)  in spics_request()  argument
93 	struct spear_spics *spics = gpiochip_get_data(chip);  in spics_request()
96 	if (!spics->use_count++) {  in spics_request()
97 		tmp = readl_relaxed(spics->base + spics->perip_cfg);  in spics_request()
98 		tmp |= 0x1 << spics->sw_enable_bit;  in spics_request()
99 		tmp |= 0x1 << spics->cs_value_bit;  in spics_request()
100 		writel_relaxed(tmp, spics->base + spics->perip_cfg);  in spics_request()
106 static void spics_free(struct gpio_chip *chip, unsigned offset)  in spics_free()  argument
108 	struct spear_spics *spics = gpiochip_get_data(chip);  in spics_free()
111 	if (!--spics->use_count) {  in spics_free()
112 		tmp = readl_relaxed(spics->base + spics->perip_cfg);  in spics_free()
113 		tmp &= ~(0x1 << spics->sw_enable_bit);  in spics_free()
114 		writel_relaxed(tmp, spics->base + spics->perip_cfg);  in spics_free()
120 	struct device_node *np = pdev->dev.of_node;  in spics_gpio_probe()
123 	spics = devm_kzalloc(&pdev->dev, sizeof(*spics), GFP_KERNEL);  in spics_gpio_probe()
125 		return -ENOMEM;  in spics_gpio_probe()
127 	spics->base = devm_platform_ioremap_resource(pdev, 0);  in spics_gpio_probe()
128 	if (IS_ERR(spics->base))  in spics_gpio_probe()
129 		return PTR_ERR(spics->base);  in spics_gpio_probe()
131 	if (of_property_read_u32(np, "st-spics,peripcfg-reg",  in spics_gpio_probe()
132 				&spics->perip_cfg))  in spics_gpio_probe()
134 	if (of_property_read_u32(np, "st-spics,sw-enable-bit",  in spics_gpio_probe()
135 				&spics->sw_enable_bit))  in spics_gpio_probe()
137 	if (of_property_read_u32(np, "st-spics,cs-value-bit",  in spics_gpio_probe()
138 				&spics->cs_value_bit))  in spics_gpio_probe()
140 	if (of_property_read_u32(np, "st-spics,cs-enable-mask",  in spics_gpio_probe()
141 				&spics->cs_enable_mask))  in spics_gpio_probe()
143 	if (of_property_read_u32(np, "st-spics,cs-enable-shift",  in spics_gpio_probe()
144 				&spics->cs_enable_shift))  in spics_gpio_probe()
147 	spics->chip.ngpio = NUM_OF_GPIO;  in spics_gpio_probe()
148 	spics->chip.base = -1;  in spics_gpio_probe()
149 	spics->chip.request = spics_request;  in spics_gpio_probe()
150 	spics->chip.free = spics_free;  in spics_gpio_probe()
151 	spics->chip.direction_input = spics_direction_input;  in spics_gpio_probe()
152 	spics->chip.direction_output = spics_direction_output;  in spics_gpio_probe()
153 	spics->chip.get = spics_get_value;  in spics_gpio_probe()
154 	spics->chip.set = spics_set_value;  in spics_gpio_probe()
155 	spics->chip.label = dev_name(&pdev->dev);  in spics_gpio_probe()
156 	spics->chip.parent = &pdev->dev;  in spics_gpio_probe()
157 	spics->chip.owner = THIS_MODULE;  in spics_gpio_probe()
158 	spics->last_off = -1;  in spics_gpio_probe()
160 	return devm_gpiochip_add_data(&pdev->dev, &spics->chip, spics);  in spics_gpio_probe()
163 	dev_err(&pdev->dev, "DT probe failed\n");  in spics_gpio_probe()
164 	return -EINVAL;  in spics_gpio_probe()
168 	{ .compatible = "st,spear-spics-gpio" },
175 		.name = "spear-spics-gpio",