From 641615abfac0b7c5e6f242a6db77f7690925b443 Mon Sep 17 00:00:00 2001 From: Samu Onkalo Date: Mon, 14 Dec 2009 18:01:41 -0800 Subject: [PATCH] lis3lv02d: proper power on sequence MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Lis3 accelerometer sensors have quite long power on delay (up to 125 ms). This patch adds necessary delay to power on sequence for currently supported lis3 chips. Signed-off-by: Samu Onkalo Tested-by: Éric Piel Acked-by: Éric Piel Cc: Pavel Machek Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/hwmon/lis3lv02d.c | 41 ++++++++++++++++++++++++++------------- drivers/hwmon/lis3lv02d.h | 1 + 2 files changed, 28 insertions(+), 14 deletions(-) diff --git a/drivers/hwmon/lis3lv02d.c b/drivers/hwmon/lis3lv02d.c index b12ee359d90e..39b9ac8e18ed 100644 --- a/drivers/hwmon/lis3lv02d.c +++ b/drivers/hwmon/lis3lv02d.c @@ -50,6 +50,9 @@ * joystick. */ +#define LIS3_PWRON_DELAY_WAI_12B (5000) +#define LIS3_PWRON_DELAY_WAI_8B (3000) + struct lis3lv02d lis3_dev = { .misc_wait = __WAIT_QUEUE_HEAD_INITIALIZER(lis3_dev.misc_wait), }; @@ -112,6 +115,24 @@ static void lis3lv02d_get_xyz(struct lis3lv02d *lis3, int *x, int *y, int *z) *z = lis3lv02d_get_axis(lis3->ac.z, position); } +/* conversion btw sampling rate and the register values */ +static int lis3_12_rates[4] = {40, 160, 640, 2560}; +static int lis3_8_rates[2] = {100, 400}; + +static int lis3lv02d_get_odr(void) +{ + u8 ctrl; + int val; + + lis3_dev.read(&lis3_dev, CTRL_REG1, &ctrl); + + if (lis3_dev.whoami == WAI_12B) + val = lis3_12_rates[(ctrl & (CTRL1_DF0 | CTRL1_DF1)) >> 4]; + else + val = lis3_8_rates[(ctrl & CTRL1_DR) >> 7]; + return val; +} + void lis3lv02d_poweroff(struct lis3lv02d *lis3) { /* disable X,Y,Z axis and power down */ @@ -125,6 +146,9 @@ void lis3lv02d_poweron(struct lis3lv02d *lis3) lis3->init(lis3); + /* LIS3 power on delay is quite long */ + msleep(lis3->pwron_delay / lis3lv02d_get_odr()); + /* * Common configuration * BDU: (12 bits sensors only) LSB and MSB values are not updated until @@ -364,23 +388,10 @@ static ssize_t lis3lv02d_calibrate_store(struct device *dev, return count; } -/* conversion btw sampling rate and the register values */ -static int lis3_12_rates[4] = {40, 160, 640, 2560}; -static int lis3_8_rates[2] = {100, 400}; static ssize_t lis3lv02d_rate_show(struct device *dev, struct device_attribute *attr, char *buf) { - u8 ctrl; - int val; - - lis3_dev.read(&lis3_dev, CTRL_REG1, &ctrl); - - if (lis3_dev.whoami == WAI_12B) - val = lis3_12_rates[(ctrl & (CTRL1_DF0 | CTRL1_DF1)) >> 4]; - else - val = lis3_8_rates[(ctrl & CTRL1_DR) >> 7]; - - return sprintf(buf, "%d\n", val); + return sprintf(buf, "%d\n", lis3lv02d_get_odr()); } static DEVICE_ATTR(position, S_IRUGO, lis3lv02d_position_show, NULL); @@ -430,11 +441,13 @@ int lis3lv02d_init_device(struct lis3lv02d *dev) printk(KERN_INFO DRIVER_NAME ": 12 bits sensor found\n"); dev->read_data = lis3lv02d_read_12; dev->mdps_max_val = 2048; + dev->pwron_delay = LIS3_PWRON_DELAY_WAI_12B; break; case WAI_8B: printk(KERN_INFO DRIVER_NAME ": 8 bits sensor found\n"); dev->read_data = lis3lv02d_read_8; dev->mdps_max_val = 128; + dev->pwron_delay = LIS3_PWRON_DELAY_WAI_8B; break; default: printk(KERN_ERR DRIVER_NAME diff --git a/drivers/hwmon/lis3lv02d.h b/drivers/hwmon/lis3lv02d.h index c6ae507e4f1e..c57f21f45676 100644 --- a/drivers/hwmon/lis3lv02d.h +++ b/drivers/hwmon/lis3lv02d.h @@ -202,6 +202,7 @@ struct lis3lv02d { u8 whoami; /* indicates measurement precision */ s16 (*read_data) (struct lis3lv02d *lis3, int reg); int mdps_max_val; + int pwron_delay; struct input_polled_dev *idev; /* input device */ struct platform_device *pdev; /* platform device */