From a253aaef60a37bddfa84846353edeb62a6acf5b3 Mon Sep 17 00:00:00 2001 From: Samu Onkalo Date: Mon, 14 Dec 2009 18:01:44 -0800 Subject: [PATCH] lis3: sysfs entry for setting chip measurement rate MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit It is possible to read position information at the chip measurement rate via sysfs. This patch adds possibility to configure chip measurement rate. Signed-off-by: Samu Onkalo Signed-off-by: Éric Piel Cc: Pavel Machek Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/hwmon/lis3lv02d.c | 51 ++++++++++++++++++++++++++++++++++++++++------- drivers/hwmon/lis3lv02d.h | 2 ++ 2 files changed, 46 insertions(+), 7 deletions(-) diff --git a/drivers/hwmon/lis3lv02d.c b/drivers/hwmon/lis3lv02d.c index 02ac5fa..ba97ed8 100644 --- a/drivers/hwmon/lis3lv02d.c +++ b/drivers/hwmon/lis3lv02d.c @@ -121,18 +121,35 @@ static void lis3lv02d_get_xyz(struct lis3lv02d *lis3, int *x, int *y, int *z) static int lis3_12_rates[4] = {40, 160, 640, 2560}; static int lis3_8_rates[2] = {100, 400}; +/* ODR is Output Data Rate */ static int lis3lv02d_get_odr(void) { u8 ctrl; - int val; + int shift; lis3_dev.read(&lis3_dev, CTRL_REG1, &ctrl); + ctrl &= lis3_dev.odr_mask; + shift = ffs(lis3_dev.odr_mask) - 1; + return lis3_dev.odrs[(ctrl >> shift)]; +} - 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; +static int lis3lv02d_set_odr(int rate) +{ + u8 ctrl; + int i, len, shift; + + lis3_dev.read(&lis3_dev, CTRL_REG1, &ctrl); + ctrl &= ~lis3_dev.odr_mask; + len = 1 << hweight_long(lis3_dev.odr_mask); /* # of possible values */ + shift = ffs(lis3_dev.odr_mask) - 1; + + for (i = 0; i < len; i++) + if (lis3_dev.odrs[i] == rate) { + lis3_dev.write(&lis3_dev, CTRL_REG1, + ctrl | (i << shift)); + return 0; + } + return -EINVAL; } static int lis3lv02d_selftest(struct lis3lv02d *lis3, s16 results[3]) @@ -433,9 +450,25 @@ static ssize_t lis3lv02d_rate_show(struct device *dev, return sprintf(buf, "%d\n", lis3lv02d_get_odr()); } +static ssize_t lis3lv02d_rate_set(struct device *dev, + struct device_attribute *attr, const char *buf, + size_t count) +{ + unsigned long rate; + + if (strict_strtoul(buf, 0, &rate)) + return -EINVAL; + + if (lis3lv02d_set_odr(rate)) + return -EINVAL; + + return count; +} + static DEVICE_ATTR(selftest, S_IRUSR, lis3lv02d_selftest_show, NULL); static DEVICE_ATTR(position, S_IRUGO, lis3lv02d_position_show, NULL); -static DEVICE_ATTR(rate, S_IRUGO, lis3lv02d_rate_show, NULL); +static DEVICE_ATTR(rate, S_IRUGO | S_IWUSR, lis3lv02d_rate_show, + lis3lv02d_rate_set); static struct attribute *lis3lv02d_attributes[] = { &dev_attr_selftest.attr, @@ -480,12 +513,16 @@ int lis3lv02d_init_device(struct lis3lv02d *dev) dev->read_data = lis3lv02d_read_12; dev->mdps_max_val = 2048; dev->pwron_delay = LIS3_PWRON_DELAY_WAI_12B; + dev->odrs = lis3_12_rates; + dev->odr_mask = CTRL1_DF0 | CTRL1_DF1; 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; + dev->odrs = lis3_8_rates; + dev->odr_mask = CTRL1_DR; break; default: printk(KERN_ERR DRIVER_NAME diff --git a/drivers/hwmon/lis3lv02d.h b/drivers/hwmon/lis3lv02d.h index 1e9fb03..f73c786 100644 --- a/drivers/hwmon/lis3lv02d.h +++ b/drivers/hwmon/lis3lv02d.h @@ -208,6 +208,8 @@ struct lis3lv02d { int (*write) (struct lis3lv02d *lis3, int reg, u8 val); int (*read) (struct lis3lv02d *lis3, int reg, u8 *ret); + int *odrs; /* Supported output data rates */ + u8 odr_mask; /* ODR bit mask */ u8 whoami; /* indicates measurement precision */ s16 (*read_data) (struct lis3lv02d *lis3, int reg); int mdps_max_val; -- 1.8.2.3