diff options
Diffstat (limited to 'target/linux/brcm2708/patches-4.9/0058-enabling-the-realtime-clock-1-wire-chip-DS1307-and-1.patch')
| -rw-r--r-- | target/linux/brcm2708/patches-4.9/0058-enabling-the-realtime-clock-1-wire-chip-DS1307-and-1.patch | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.9/0058-enabling-the-realtime-clock-1-wire-chip-DS1307-and-1.patch b/target/linux/brcm2708/patches-4.9/0058-enabling-the-realtime-clock-1-wire-chip-DS1307-and-1.patch new file mode 100644 index 0000000000..5c3e0641cb --- /dev/null +++ b/target/linux/brcm2708/patches-4.9/0058-enabling-the-realtime-clock-1-wire-chip-DS1307-and-1.patch @@ -0,0 +1,242 @@ +From d387edf492067aa0d298b90829b784f640375e7c Mon Sep 17 00:00:00 2001 +From: popcornmix <popcornmix@gmail.com> +Date: Wed, 8 May 2013 11:46:50 +0100 +Subject: [PATCH] enabling the realtime clock 1-wire chip DS1307 and 1-wire on + GPIO4 (as a module) + +1-wire: Add support for configuring pin for w1-gpio kernel module +See: https://github.com/raspberrypi/linux/pull/457 + +Add bitbanging pullups, use them for w1-gpio + +Allows parasite power to work, uses module option pullup=1 + +bcm2708: Ensure 1-wire pullup is disabled by default, and expose as module parameter + +Signed-off-by: Alex J Lennon <ajlennon@dynamicdevices.co.uk> + +w1-gpio: Add gpiopin module parameter and correctly free up gpio pull-up pin, if set + +Signed-off-by: Alex J Lennon <ajlennon@dynamicdevices.co.uk> + +w1-gpio: Sort out the pullup/parasitic power tangle +--- + drivers/w1/masters/w1-gpio.c | 69 ++++++++++++++++++++++++++++++++++++++++---- + drivers/w1/w1.h | 6 ++++ + drivers/w1/w1_int.c | 14 +++++++++ + drivers/w1/w1_io.c | 18 ++++++++++-- + include/linux/w1-gpio.h | 1 + + 5 files changed, 99 insertions(+), 9 deletions(-) + +--- a/drivers/w1/masters/w1-gpio.c ++++ b/drivers/w1/masters/w1-gpio.c +@@ -23,6 +23,19 @@ + #include "../w1.h" + #include "../w1_int.h" + ++static int w1_gpio_pullup = 0; ++static int w1_gpio_pullup_orig = 0; ++module_param_named(pullup, w1_gpio_pullup, int, 0); ++MODULE_PARM_DESC(pullup, "Enable parasitic power (power on data) mode"); ++static int w1_gpio_pullup_pin = -1; ++static int w1_gpio_pullup_pin_orig = -1; ++module_param_named(extpullup, w1_gpio_pullup_pin, int, 0); ++MODULE_PARM_DESC(extpullup, "GPIO external pullup pin number"); ++static int w1_gpio_pin = -1; ++static int w1_gpio_pin_orig = -1; ++module_param_named(gpiopin, w1_gpio_pin, int, 0); ++MODULE_PARM_DESC(gpiopin, "GPIO pin number"); ++ + static u8 w1_gpio_set_pullup(void *data, int delay) + { + struct w1_gpio_platform_data *pdata = data; +@@ -67,6 +80,16 @@ static u8 w1_gpio_read_bit(void *data) + return gpio_get_value(pdata->pin) ? 1 : 0; + } + ++static void w1_gpio_bitbang_pullup(void *data, u8 on) ++{ ++ struct w1_gpio_platform_data *pdata = data; ++ ++ if (on) ++ gpio_direction_output(pdata->pin, 1); ++ else ++ gpio_direction_input(pdata->pin); ++} ++ + #if defined(CONFIG_OF) + static const struct of_device_id w1_gpio_dt_ids[] = { + { .compatible = "w1-gpio" }, +@@ -80,6 +103,7 @@ static int w1_gpio_probe_dt(struct platf + struct w1_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev); + struct device_node *np = pdev->dev.of_node; + int gpio; ++ u32 value; + + pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); + if (!pdata) +@@ -88,6 +112,9 @@ static int w1_gpio_probe_dt(struct platf + if (of_get_property(np, "linux,open-drain", NULL)) + pdata->is_open_drain = 1; + ++ if (of_property_read_u32(np, "rpi,parasitic-power", &value) == 0) ++ pdata->parasitic_power = (value != 0); ++ + gpio = of_get_gpio(np, 0); + if (gpio < 0) { + if (gpio != -EPROBE_DEFER) +@@ -103,7 +130,7 @@ static int w1_gpio_probe_dt(struct platf + if (gpio == -EPROBE_DEFER) + return gpio; + /* ignore other errors as the pullup gpio is optional */ +- pdata->ext_pullup_enable_pin = gpio; ++ pdata->ext_pullup_enable_pin = (gpio >= 0) ? gpio : -1; + + pdev->dev.platform_data = pdata; + +@@ -113,13 +140,15 @@ static int w1_gpio_probe_dt(struct platf + static int w1_gpio_probe(struct platform_device *pdev) + { + struct w1_bus_master *master; +- struct w1_gpio_platform_data *pdata; ++ struct w1_gpio_platform_data *pdata = pdev->dev.platform_data; + int err; + +- if (of_have_populated_dt()) { +- err = w1_gpio_probe_dt(pdev); +- if (err < 0) +- return err; ++ if(pdata == NULL) { ++ if (of_have_populated_dt()) { ++ err = w1_gpio_probe_dt(pdev); ++ if (err < 0) ++ return err; ++ } + } + + pdata = dev_get_platdata(&pdev->dev); +@@ -136,6 +165,22 @@ static int w1_gpio_probe(struct platform + return -ENOMEM; + } + ++ w1_gpio_pin_orig = pdata->pin; ++ w1_gpio_pullup_pin_orig = pdata->ext_pullup_enable_pin; ++ w1_gpio_pullup_orig = pdata->parasitic_power; ++ ++ if(gpio_is_valid(w1_gpio_pin)) { ++ pdata->pin = w1_gpio_pin; ++ pdata->ext_pullup_enable_pin = -1; ++ pdata->parasitic_power = -1; ++ } ++ pdata->parasitic_power |= w1_gpio_pullup; ++ if(gpio_is_valid(w1_gpio_pullup_pin)) { ++ pdata->ext_pullup_enable_pin = w1_gpio_pullup_pin; ++ } ++ ++ dev_info(&pdev->dev, "gpio pin %d, external pullup pin %d, parasitic power %d\n", pdata->pin, pdata->ext_pullup_enable_pin, pdata->parasitic_power); ++ + err = devm_gpio_request(&pdev->dev, pdata->pin, "w1"); + if (err) { + dev_err(&pdev->dev, "gpio_request (pin) failed\n"); +@@ -165,6 +210,14 @@ static int w1_gpio_probe(struct platform + master->set_pullup = w1_gpio_set_pullup; + } + ++ if (pdata->parasitic_power) { ++ if (pdata->is_open_drain) ++ printk(KERN_ERR "w1-gpio 'pullup'(parasitic power) " ++ "option doesn't work with open drain GPIO\n"); ++ else ++ master->bitbang_pullup = w1_gpio_bitbang_pullup; ++ } ++ + err = w1_add_master_device(master); + if (err) { + dev_err(&pdev->dev, "w1_add_master device failed\n"); +@@ -195,6 +248,10 @@ static int w1_gpio_remove(struct platfor + + w1_remove_master_device(master); + ++ pdata->pin = w1_gpio_pin_orig; ++ pdata->ext_pullup_enable_pin = w1_gpio_pullup_pin_orig; ++ pdata->parasitic_power = w1_gpio_pullup_orig; ++ + return 0; + } + +--- a/drivers/w1/w1.h ++++ b/drivers/w1/w1.h +@@ -173,6 +173,12 @@ struct w1_bus_master + + u8 (*set_pullup)(void *, int); + ++ /** ++ * Turns the pullup on/off in bitbanging mode, takes an on/off argument. ++ * @return -1=Error, 0=completed ++ */ ++ void (*bitbang_pullup) (void *, u8); ++ + void (*search)(void *, struct w1_master *, + u8, w1_slave_found_callback); + }; +--- a/drivers/w1/w1_int.c ++++ b/drivers/w1/w1_int.c +@@ -122,6 +122,20 @@ int w1_add_master_device(struct w1_bus_m + return(-EINVAL); + } + ++ /* bitbanging hardware uses bitbang_pullup, other hardware uses set_pullup ++ * and takes care of timing itself */ ++ if (!master->write_byte && !master->touch_bit && master->set_pullup) { ++ printk(KERN_ERR "w1_add_master_device: set_pullup requires " ++ "write_byte or touch_bit, disabling\n"); ++ master->set_pullup = NULL; ++ } ++ ++ if (master->set_pullup && master->bitbang_pullup) { ++ printk(KERN_ERR "w1_add_master_device: set_pullup should not " ++ "be set when bitbang_pullup is used, disabling\n"); ++ master->set_pullup = NULL; ++ } ++ + /* Lock until the device is added (or not) to w1_masters. */ + mutex_lock(&w1_mlock); + /* Search for the first available id (starting at 1). */ +--- a/drivers/w1/w1_io.c ++++ b/drivers/w1/w1_io.c +@@ -134,10 +134,22 @@ static void w1_pre_write(struct w1_maste + static void w1_post_write(struct w1_master *dev) + { + if (dev->pullup_duration) { +- if (dev->enable_pullup && dev->bus_master->set_pullup) +- dev->bus_master->set_pullup(dev->bus_master->data, 0); +- else ++ if (dev->enable_pullup) { ++ if (dev->bus_master->set_pullup) { ++ dev->bus_master->set_pullup(dev-> ++ bus_master->data, ++ 0); ++ } else if (dev->bus_master->bitbang_pullup) { ++ dev->bus_master-> ++ bitbang_pullup(dev->bus_master->data, 1); + msleep(dev->pullup_duration); ++ dev->bus_master-> ++ bitbang_pullup(dev->bus_master->data, 0); ++ } ++ } else { ++ msleep(dev->pullup_duration); ++ } ++ + dev->pullup_duration = 0; + } + } +--- a/include/linux/w1-gpio.h ++++ b/include/linux/w1-gpio.h +@@ -18,6 +18,7 @@ + struct w1_gpio_platform_data { + unsigned int pin; + unsigned int is_open_drain:1; ++ unsigned int parasitic_power:1; + void (*enable_external_pullup)(int enable); + unsigned int ext_pullup_enable_pin; + unsigned int pullup_duration; |