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168 lines
4.1 KiB
168 lines
4.1 KiB
// SPDX-License-Identifier: GPL-2.0+ |
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/* |
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* Copyright (C) 2019 Bootlin |
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* Author: Paul Kocialkowski <[email protected]> |
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*/ |
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#include <linux/err.h> |
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#include <linux/gpio/driver.h> |
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#include <linux/module.h> |
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#include <linux/of.h> |
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#include <linux/of_device.h> |
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#include <linux/of_address.h> |
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#include <linux/platform_device.h> |
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#include <linux/regmap.h> |
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#include <linux/mfd/syscon.h> |
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#define LOGICVC_CTRL_REG 0x40 |
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#define LOGICVC_CTRL_GPIO_SHIFT 11 |
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#define LOGICVC_CTRL_GPIO_BITS 5 |
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#define LOGICVC_POWER_CTRL_REG 0x78 |
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#define LOGICVC_POWER_CTRL_GPIO_SHIFT 0 |
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#define LOGICVC_POWER_CTRL_GPIO_BITS 4 |
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struct logicvc_gpio { |
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struct gpio_chip chip; |
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struct regmap *regmap; |
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}; |
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static void logicvc_gpio_offset(struct logicvc_gpio *logicvc, unsigned offset, |
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unsigned int *reg, unsigned int *bit) |
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{ |
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if (offset >= LOGICVC_CTRL_GPIO_BITS) { |
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*reg = LOGICVC_POWER_CTRL_REG; |
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/* To the (virtual) power ctrl offset. */ |
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offset -= LOGICVC_CTRL_GPIO_BITS; |
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/* To the actual bit offset in reg. */ |
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offset += LOGICVC_POWER_CTRL_GPIO_SHIFT; |
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} else { |
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*reg = LOGICVC_CTRL_REG; |
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/* To the actual bit offset in reg. */ |
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offset += LOGICVC_CTRL_GPIO_SHIFT; |
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} |
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*bit = BIT(offset); |
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} |
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static int logicvc_gpio_get(struct gpio_chip *chip, unsigned offset) |
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{ |
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struct logicvc_gpio *logicvc = gpiochip_get_data(chip); |
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unsigned int reg, bit, value; |
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int ret; |
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logicvc_gpio_offset(logicvc, offset, ®, &bit); |
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ret = regmap_read(logicvc->regmap, reg, &value); |
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if (ret) |
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return ret; |
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return !!(value & bit); |
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} |
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static void logicvc_gpio_set(struct gpio_chip *chip, unsigned offset, int value) |
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{ |
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struct logicvc_gpio *logicvc = gpiochip_get_data(chip); |
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unsigned int reg, bit; |
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logicvc_gpio_offset(logicvc, offset, ®, &bit); |
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regmap_update_bits(logicvc->regmap, reg, bit, value ? bit : 0); |
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} |
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static int logicvc_gpio_direction_output(struct gpio_chip *chip, |
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unsigned offset, int value) |
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{ |
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/* Pins are always configured as output, so just set the value. */ |
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logicvc_gpio_set(chip, offset, value); |
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return 0; |
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} |
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static struct regmap_config logicvc_gpio_regmap_config = { |
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.reg_bits = 32, |
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.val_bits = 32, |
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.reg_stride = 4, |
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.name = "logicvc-gpio", |
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}; |
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static int logicvc_gpio_probe(struct platform_device *pdev) |
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{ |
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struct device *dev = &pdev->dev; |
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struct device_node *of_node = dev->of_node; |
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struct logicvc_gpio *logicvc; |
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int ret; |
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logicvc = devm_kzalloc(dev, sizeof(*logicvc), GFP_KERNEL); |
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if (!logicvc) |
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return -ENOMEM; |
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/* Try to get regmap from parent first. */ |
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logicvc->regmap = syscon_node_to_regmap(of_node->parent); |
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/* Grab our own regmap if that fails. */ |
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if (IS_ERR(logicvc->regmap)) { |
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struct resource res; |
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void __iomem *base; |
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ret = of_address_to_resource(of_node, 0, &res); |
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if (ret) { |
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dev_err(dev, "Failed to get resource from address\n"); |
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return ret; |
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} |
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base = devm_ioremap_resource(dev, &res); |
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if (IS_ERR(base)) |
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return PTR_ERR(base); |
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logicvc_gpio_regmap_config.max_register = resource_size(&res) - |
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logicvc_gpio_regmap_config.reg_stride; |
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logicvc->regmap = |
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devm_regmap_init_mmio(dev, base, |
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&logicvc_gpio_regmap_config); |
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if (IS_ERR(logicvc->regmap)) { |
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dev_err(dev, "Failed to create regmap for I/O\n"); |
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return PTR_ERR(logicvc->regmap); |
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} |
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} |
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logicvc->chip.parent = dev; |
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logicvc->chip.owner = THIS_MODULE; |
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logicvc->chip.label = dev_name(dev); |
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logicvc->chip.base = -1; |
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logicvc->chip.ngpio = LOGICVC_CTRL_GPIO_BITS + |
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LOGICVC_POWER_CTRL_GPIO_BITS; |
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logicvc->chip.get = logicvc_gpio_get; |
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logicvc->chip.set = logicvc_gpio_set; |
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logicvc->chip.direction_output = logicvc_gpio_direction_output; |
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platform_set_drvdata(pdev, logicvc); |
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return devm_gpiochip_add_data(dev, &logicvc->chip, logicvc); |
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} |
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static const struct of_device_id logicivc_gpio_of_table[] = { |
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{ |
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.compatible = "xylon,logicvc-3.02.a-gpio", |
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}, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(of, logicivc_gpio_of_table); |
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static struct platform_driver logicvc_gpio_driver = { |
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.driver = { |
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.name = "gpio-logicvc", |
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.of_match_table = logicivc_gpio_of_table, |
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}, |
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.probe = logicvc_gpio_probe, |
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}; |
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module_platform_driver(logicvc_gpio_driver); |
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MODULE_AUTHOR("Paul Kocialkowski <[email protected]>"); |
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MODULE_DESCRIPTION("Xylon LogiCVC GPIO driver"); |
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MODULE_LICENSE("GPL");
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