Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  * w1-gpio - GPIO w1 bus master driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  * Copyright (C) 2007 Ville Syrjala <syrjala@sci.fi>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) #include <linux/platform_device.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) #include <linux/w1-gpio.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #include <linux/gpio/consumer.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) #include <linux/of_platform.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include <linux/err.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) #include <linux/of.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) #include <linux/delay.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) #include <linux/w1.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) static u8 w1_gpio_set_pullup(void *data, int delay)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) 	struct w1_gpio_platform_data *pdata = data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) 	if (delay) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) 		pdata->pullup_duration = delay;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) 		if (pdata->pullup_duration) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) 			/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 			 * This will OVERRIDE open drain emulation and force-pull
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) 			 * the line high for some time.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) 			 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 			gpiod_set_raw_value(pdata->gpiod, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) 			msleep(pdata->pullup_duration);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 			/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 			 * This will simply set the line as input since we are doing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 			 * open drain emulation in the GPIO library.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 			 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 			gpiod_set_value(pdata->gpiod, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 		pdata->pullup_duration = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) static void w1_gpio_write_bit(void *data, u8 bit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 	struct w1_gpio_platform_data *pdata = data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 	gpiod_set_value(pdata->gpiod, bit);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) static u8 w1_gpio_read_bit(void *data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 	struct w1_gpio_platform_data *pdata = data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 	return gpiod_get_value(pdata->gpiod) ? 1 : 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) #if defined(CONFIG_OF)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) static const struct of_device_id w1_gpio_dt_ids[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 	{ .compatible = "w1-gpio" },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 	{}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) MODULE_DEVICE_TABLE(of, w1_gpio_dt_ids);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) static int w1_gpio_probe(struct platform_device *pdev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 	struct w1_bus_master *master;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 	struct w1_gpio_platform_data *pdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 	struct device *dev = &pdev->dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 	struct device_node *np = dev->of_node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 	/* Enforce open drain mode by default */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 	enum gpiod_flags gflags = GPIOD_OUT_LOW_OPEN_DRAIN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 	if (of_have_populated_dt()) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 		pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 		if (!pdata)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 			return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 		 * This parameter means that something else than the gpiolib has
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 		 * already set the line into open drain mode, so we should just
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 		 * driver it high/low like we are in full control of the line and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 		 * open drain will happen transparently.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 		if (of_get_property(np, "linux,open-drain", NULL))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 			gflags = GPIOD_OUT_LOW;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 		pdev->dev.platform_data = pdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 	pdata = dev_get_platdata(dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 	if (!pdata) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 		dev_err(dev, "No configuration data\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 		return -ENXIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 	master = devm_kzalloc(dev, sizeof(struct w1_bus_master),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 			GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 	if (!master) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 		dev_err(dev, "Out of memory\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 		return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 	pdata->gpiod = devm_gpiod_get_index(dev, NULL, 0, gflags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 	if (IS_ERR(pdata->gpiod)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 		dev_err(dev, "gpio_request (pin) failed\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 		return PTR_ERR(pdata->gpiod);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 	pdata->pullup_gpiod =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 		devm_gpiod_get_index_optional(dev, NULL, 1, GPIOD_OUT_LOW);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 	if (IS_ERR(pdata->pullup_gpiod)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 		dev_err(dev, "gpio_request_one "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 			"(ext_pullup_enable_pin) failed\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 		return PTR_ERR(pdata->pullup_gpiod);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 	master->data = pdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 	master->read_bit = w1_gpio_read_bit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 	gpiod_direction_output(pdata->gpiod, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 	master->write_bit = w1_gpio_write_bit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 	 * If we are using open drain emulation from the GPIO library,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 	 * we need to use this pullup function that hammers the line
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 	 * high using a raw accessor to provide pull-up for the w1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 	 * line.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	if (gflags == GPIOD_OUT_LOW_OPEN_DRAIN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 		master->set_pullup = w1_gpio_set_pullup;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 	err = w1_add_master_device(master);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 	if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 		dev_err(dev, "w1_add_master device failed\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 		return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 	if (pdata->enable_external_pullup)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 		pdata->enable_external_pullup(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 	if (pdata->pullup_gpiod)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 		gpiod_set_value(pdata->pullup_gpiod, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 	platform_set_drvdata(pdev, master);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) static int w1_gpio_remove(struct platform_device *pdev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 	struct w1_bus_master *master = platform_get_drvdata(pdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 	struct w1_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 	if (pdata->enable_external_pullup)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 		pdata->enable_external_pullup(0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 	if (pdata->pullup_gpiod)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 		gpiod_set_value(pdata->pullup_gpiod, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 	w1_remove_master_device(master);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) static int __maybe_unused w1_gpio_suspend(struct device *dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 	struct w1_gpio_platform_data *pdata = dev_get_platdata(dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 	if (pdata->enable_external_pullup)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 		pdata->enable_external_pullup(0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) static int __maybe_unused w1_gpio_resume(struct device *dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 	struct w1_gpio_platform_data *pdata = dev_get_platdata(dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 	if (pdata->enable_external_pullup)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 		pdata->enable_external_pullup(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) static SIMPLE_DEV_PM_OPS(w1_gpio_pm_ops, w1_gpio_suspend, w1_gpio_resume);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) static struct platform_driver w1_gpio_driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 	.driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 		.name	= "w1-gpio",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 		.pm	= &w1_gpio_pm_ops,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 		.of_match_table = of_match_ptr(w1_gpio_dt_ids),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 	},
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 	.probe = w1_gpio_probe,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 	.remove = w1_gpio_remove,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) module_platform_driver(w1_gpio_driver);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) MODULE_DESCRIPTION("GPIO w1 bus master driver");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) MODULE_AUTHOR("Ville Syrjala <syrjala@sci.fi>");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) MODULE_LICENSE("GPL");