diff options
author | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 12:17:53 -0700 |
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committer | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 15:44:42 -0700 |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/drivers/w1/masters/w1-gpio.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/drivers/w1/masters/w1-gpio.c')
-rw-r--r-- | kernel/drivers/w1/masters/w1-gpio.c | 243 |
1 files changed, 243 insertions, 0 deletions
diff --git a/kernel/drivers/w1/masters/w1-gpio.c b/kernel/drivers/w1/masters/w1-gpio.c new file mode 100644 index 000000000..8f7848c62 --- /dev/null +++ b/kernel/drivers/w1/masters/w1-gpio.c @@ -0,0 +1,243 @@ +/* + * w1-gpio - GPIO w1 bus master driver + * + * Copyright (C) 2007 Ville Syrjala <syrjala@sci.fi> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation. + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/w1-gpio.h> +#include <linux/gpio.h> +#include <linux/of_platform.h> +#include <linux/of_gpio.h> +#include <linux/err.h> +#include <linux/of.h> +#include <linux/delay.h> + +#include "../w1.h" +#include "../w1_int.h" + +static u8 w1_gpio_set_pullup(void *data, int delay) +{ + struct w1_gpio_platform_data *pdata = data; + + if (delay) { + pdata->pullup_duration = delay; + } else { + if (pdata->pullup_duration) { + gpio_direction_output(pdata->pin, 1); + + msleep(pdata->pullup_duration); + + gpio_direction_input(pdata->pin); + } + pdata->pullup_duration = 0; + } + + return 0; +} + +static void w1_gpio_write_bit_dir(void *data, u8 bit) +{ + struct w1_gpio_platform_data *pdata = data; + + if (bit) + gpio_direction_input(pdata->pin); + else + gpio_direction_output(pdata->pin, 0); +} + +static void w1_gpio_write_bit_val(void *data, u8 bit) +{ + struct w1_gpio_platform_data *pdata = data; + + gpio_set_value(pdata->pin, bit); +} + +static u8 w1_gpio_read_bit(void *data) +{ + struct w1_gpio_platform_data *pdata = data; + + return gpio_get_value(pdata->pin) ? 1 : 0; +} + +#if defined(CONFIG_OF) +static const struct of_device_id w1_gpio_dt_ids[] = { + { .compatible = "w1-gpio" }, + {} +}; +MODULE_DEVICE_TABLE(of, w1_gpio_dt_ids); +#endif + +static int w1_gpio_probe_dt(struct platform_device *pdev) +{ + struct w1_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev); + struct device_node *np = pdev->dev.of_node; + int gpio; + + pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); + if (!pdata) + return -ENOMEM; + + if (of_get_property(np, "linux,open-drain", NULL)) + pdata->is_open_drain = 1; + + gpio = of_get_gpio(np, 0); + if (gpio < 0) { + if (gpio != -EPROBE_DEFER) + dev_err(&pdev->dev, + "Failed to parse gpio property for data pin (%d)\n", + gpio); + + return gpio; + } + pdata->pin = gpio; + + gpio = of_get_gpio(np, 1); + if (gpio == -EPROBE_DEFER) + return gpio; + /* ignore other errors as the pullup gpio is optional */ + pdata->ext_pullup_enable_pin = gpio; + + pdev->dev.platform_data = pdata; + + return 0; +} + +static int w1_gpio_probe(struct platform_device *pdev) +{ + struct w1_bus_master *master; + struct w1_gpio_platform_data *pdata; + int err; + + if (of_have_populated_dt()) { + err = w1_gpio_probe_dt(pdev); + if (err < 0) + return err; + } + + pdata = dev_get_platdata(&pdev->dev); + + if (!pdata) { + dev_err(&pdev->dev, "No configuration data\n"); + return -ENXIO; + } + + master = devm_kzalloc(&pdev->dev, sizeof(struct w1_bus_master), + GFP_KERNEL); + if (!master) { + dev_err(&pdev->dev, "Out of memory\n"); + return -ENOMEM; + } + + err = devm_gpio_request(&pdev->dev, pdata->pin, "w1"); + if (err) { + dev_err(&pdev->dev, "gpio_request (pin) failed\n"); + return err; + } + + if (gpio_is_valid(pdata->ext_pullup_enable_pin)) { + err = devm_gpio_request_one(&pdev->dev, + pdata->ext_pullup_enable_pin, GPIOF_INIT_LOW, + "w1 pullup"); + if (err < 0) { + dev_err(&pdev->dev, "gpio_request_one " + "(ext_pullup_enable_pin) failed\n"); + return err; + } + } + + master->data = pdata; + master->read_bit = w1_gpio_read_bit; + + if (pdata->is_open_drain) { + gpio_direction_output(pdata->pin, 1); + master->write_bit = w1_gpio_write_bit_val; + } else { + gpio_direction_input(pdata->pin); + master->write_bit = w1_gpio_write_bit_dir; + master->set_pullup = w1_gpio_set_pullup; + } + + err = w1_add_master_device(master); + if (err) { + dev_err(&pdev->dev, "w1_add_master device failed\n"); + return err; + } + + if (pdata->enable_external_pullup) + pdata->enable_external_pullup(1); + + if (gpio_is_valid(pdata->ext_pullup_enable_pin)) + gpio_set_value(pdata->ext_pullup_enable_pin, 1); + + platform_set_drvdata(pdev, master); + + return 0; +} + +static int w1_gpio_remove(struct platform_device *pdev) +{ + struct w1_bus_master *master = platform_get_drvdata(pdev); + struct w1_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev); + + if (pdata->enable_external_pullup) + pdata->enable_external_pullup(0); + + if (gpio_is_valid(pdata->ext_pullup_enable_pin)) + gpio_set_value(pdata->ext_pullup_enable_pin, 0); + + w1_remove_master_device(master); + + return 0; +} + +#ifdef CONFIG_PM + +static int w1_gpio_suspend(struct platform_device *pdev, pm_message_t state) +{ + struct w1_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev); + + if (pdata->enable_external_pullup) + pdata->enable_external_pullup(0); + + return 0; +} + +static int w1_gpio_resume(struct platform_device *pdev) +{ + struct w1_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev); + + if (pdata->enable_external_pullup) + pdata->enable_external_pullup(1); + + return 0; +} + +#else +#define w1_gpio_suspend NULL +#define w1_gpio_resume NULL +#endif + +static struct platform_driver w1_gpio_driver = { + .driver = { + .name = "w1-gpio", + .of_match_table = of_match_ptr(w1_gpio_dt_ids), + }, + .probe = w1_gpio_probe, + .remove = w1_gpio_remove, + .suspend = w1_gpio_suspend, + .resume = w1_gpio_resume, +}; + +module_platform_driver(w1_gpio_driver); + +MODULE_DESCRIPTION("GPIO w1 bus master driver"); +MODULE_AUTHOR("Ville Syrjala <syrjala@sci.fi>"); +MODULE_LICENSE("GPL"); |