From 2db4a76d5f3554e9e5632c8f91828313318579c8 Mon Sep 17 00:00:00 2001 From: Samu Onkalo Date: Mon, 14 Dec 2009 18:01:43 -0800 Subject: [PATCH] lis3: selftest support MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Implement selftest feature as specified by chip manufacturer. Control: read selftest sysfs entry Response: "OK x y z" or "FAIL x y z" where x, y, and z are difference between selftest mode and normal mode. Test is passed when values are within acceptance limit values. Acceptance limits are provided via platform data. See chip spesifications for acceptance limits. If limits are not properly set, OK / FAIL decision is meaningless. However, userspace application can still make decision based on the numeric x, y, z values. Selftest is meant for HW diagnostic purposes. It is not meant to be called during normal use of the chip. It may cause false interrupt events. Selftest mode delays polling of the normal results but it doesn't cause wrong values. Chip must be in static state during selftest. Any acceration during the test causes most probably failure. Signed-off-by: Samu Onkalo Acked-by: Éric Piel Cc: Pavel Machek Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/hwmon/lis3lv02d.c | 67 ++++++++++++++++++++++++++++++++++++++- drivers/hwmon/lis3lv02d.h | 14 ++++++-- include/linux/lis3lv02d.h | 3 ++ 3 files changed, 81 insertions(+), 3 deletions(-) diff --git a/drivers/hwmon/lis3lv02d.c b/drivers/hwmon/lis3lv02d.c index 39b9ac8e18ed..55ec883e2026 100644 --- a/drivers/hwmon/lis3lv02d.c +++ b/drivers/hwmon/lis3lv02d.c @@ -106,9 +106,11 @@ static void lis3lv02d_get_xyz(struct lis3lv02d *lis3, int *x, int *y, int *z) { int position[3]; + mutex_lock(&lis3->mutex); position[0] = lis3->read_data(lis3, OUTX); position[1] = lis3->read_data(lis3, OUTY); position[2] = lis3->read_data(lis3, OUTZ); + mutex_unlock(&lis3->mutex); *x = lis3lv02d_get_axis(lis3->ac.x, position); *y = lis3lv02d_get_axis(lis3->ac.y, position); @@ -133,6 +135,55 @@ static int lis3lv02d_get_odr(void) return val; } +static int lis3lv02d_selftest(struct lis3lv02d *lis3, s16 results[3]) +{ + u8 reg; + s16 x, y, z; + u8 selftest; + int ret; + + mutex_lock(&lis3->mutex); + if (lis3_dev.whoami == WAI_12B) + selftest = CTRL1_ST; + else + selftest = CTRL1_STP; + + lis3->read(lis3, CTRL_REG1, ®); + lis3->write(lis3, CTRL_REG1, (reg | selftest)); + msleep(lis3->pwron_delay / lis3lv02d_get_odr()); + + /* Read directly to avoid axis remap */ + x = lis3->read_data(lis3, OUTX); + y = lis3->read_data(lis3, OUTY); + z = lis3->read_data(lis3, OUTZ); + + /* back to normal settings */ + lis3->write(lis3, CTRL_REG1, reg); + msleep(lis3->pwron_delay / lis3lv02d_get_odr()); + + results[0] = x - lis3->read_data(lis3, OUTX); + results[1] = y - lis3->read_data(lis3, OUTY); + results[2] = z - lis3->read_data(lis3, OUTZ); + + ret = 0; + if (lis3->pdata) { + int i; + for (i = 0; i < 3; i++) { + /* Check against selftest acceptance limits */ + if ((results[i] < lis3->pdata->st_min_limits[i]) || + (results[i] > lis3->pdata->st_max_limits[i])) { + ret = -EIO; + goto fail; + } + } + } + + /* test passed */ +fail: + mutex_unlock(&lis3->mutex); + return ret; +} + void lis3lv02d_poweroff(struct lis3lv02d *lis3) { /* disable X,Y,Z axis and power down */ @@ -365,6 +416,17 @@ void lis3lv02d_joystick_disable(void) EXPORT_SYMBOL_GPL(lis3lv02d_joystick_disable); /* Sysfs stuff */ +static ssize_t lis3lv02d_selftest_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + int result; + s16 values[3]; + + result = lis3lv02d_selftest(&lis3_dev, values); + return sprintf(buf, "%s %d %d %d\n", result == 0 ? "OK" : "FAIL", + values[0], values[1], values[2]); +} + static ssize_t lis3lv02d_position_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -394,12 +456,14 @@ static ssize_t lis3lv02d_rate_show(struct device *dev, return sprintf(buf, "%d\n", lis3lv02d_get_odr()); } +static DEVICE_ATTR(selftest, S_IRUSR, lis3lv02d_selftest_show, NULL); static DEVICE_ATTR(position, S_IRUGO, lis3lv02d_position_show, NULL); static DEVICE_ATTR(calibrate, S_IRUGO|S_IWUSR, lis3lv02d_calibrate_show, lis3lv02d_calibrate_store); static DEVICE_ATTR(rate, S_IRUGO, lis3lv02d_rate_show, NULL); static struct attribute *lis3lv02d_attributes[] = { + &dev_attr_selftest.attr, &dev_attr_position.attr, &dev_attr_calibrate.attr, &dev_attr_rate.attr, @@ -455,6 +519,8 @@ int lis3lv02d_init_device(struct lis3lv02d *dev) return -EINVAL; } + mutex_init(&dev->mutex); + lis3lv02d_add_fs(dev); lis3lv02d_poweron(dev); @@ -507,4 +573,3 @@ EXPORT_SYMBOL_GPL(lis3lv02d_init_device); MODULE_DESCRIPTION("ST LIS3LV02Dx three-axis digital accelerometer driver"); MODULE_AUTHOR("Yan Burman, Eric Piel, Pavel Machek"); MODULE_LICENSE("GPL"); - diff --git a/drivers/hwmon/lis3lv02d.h b/drivers/hwmon/lis3lv02d.h index c57f21f45676..166794cb91a3 100644 --- a/drivers/hwmon/lis3lv02d.h +++ b/drivers/hwmon/lis3lv02d.h @@ -98,7 +98,7 @@ enum lis3_who_am_i { WAI_6B = 0x52, /* 6 bits: LIS331DLF - not supported */ }; -enum lis3lv02d_ctrl1 { +enum lis3lv02d_ctrl1_12b { CTRL1_Xen = 0x01, CTRL1_Yen = 0x02, CTRL1_Zen = 0x04, @@ -107,8 +107,17 @@ enum lis3lv02d_ctrl1 { CTRL1_DF1 = 0x20, CTRL1_PD0 = 0x40, CTRL1_PD1 = 0x80, - CTRL1_DR = 0x80, /* Data rate on 8 bits */ }; + +/* Delta to ctrl1_12b version */ +enum lis3lv02d_ctrl1_8b { + CTRL1_STM = 0x08, + CTRL1_STP = 0x10, + CTRL1_FS = 0x20, + CTRL1_PD = 0x40, + CTRL1_DR = 0x80, +}; + enum lis3lv02d_ctrl2 { CTRL2_DAS = 0x01, CTRL2_SIM = 0x02, @@ -218,6 +227,7 @@ struct lis3lv02d { unsigned long misc_opened; /* bit0: whether the device is open */ struct lis3lv02d_platform_data *pdata; /* for passing board config */ + struct mutex mutex; /* Serialize poll and selftest */ }; int lis3lv02d_init_device(struct lis3lv02d *lis3); diff --git a/include/linux/lis3lv02d.h b/include/linux/lis3lv02d.h index 89701355c74f..f1ca0dcc1628 100644 --- a/include/linux/lis3lv02d.h +++ b/include/linux/lis3lv02d.h @@ -55,6 +55,9 @@ struct lis3lv02d_platform_data { s8 axis_z; int (*setup_resources)(void); int (*release_resources)(void); + /* Limits for selftest are specified in chip data sheet */ + s16 st_min_limits[3]; /* min pass limit x, y, z */ + s16 st_max_limits[3]; /* max pass limit x, y, z */ }; #endif /* __LIS3LV02D_H_ */ -- 2.20.1