]> git.openfabrics.org - ~shefty/rdma-dev.git/commitdiff
lis3: sysfs entry for setting chip measurement rate
authorSamu Onkalo <samu.p.onkalo@nokia.com>
Tue, 15 Dec 2009 02:01:44 +0000 (18:01 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 15 Dec 2009 16:53:36 +0000 (08:53 -0800)
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 <samu.p.onkalo@nokia.com>
Signed-off-by: √Čric Piel <Eric.Piel@tremplin-utc.net>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/hwmon/lis3lv02d.c
drivers/hwmon/lis3lv02d.h

index 02ac5fa5a05c138db19afeebdf7c4998fd8925b7..ba97ed8516bf7bd649bf1c65911e347c981c9cb5 100644 (file)
@@ -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
index 1e9fb03dcd5980a0b50c99fa6046d654cc3809df..f73c78603732405997986942fda16b8bbb0930a1 100644 (file)
@@ -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;