From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org,
Quentin Schulz <quentin.schulz@free-electrons.com>,
Jonathan Cameron <jic23@kernel.org>
Subject: [PATCH 4.4 11/32] iio: bmg160: reset chip when probing
Date: Mon, 10 Apr 2017 18:39:01 +0200 [thread overview]
Message-ID: <20170410163840.706501305@linuxfoundation.org> (raw)
In-Reply-To: <20170410163839.055472822@linuxfoundation.org>
4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Quentin Schulz <quentin.schulz@free-electrons.com>
commit 4bdc9029685ac03be50b320b29691766d2326c2b upstream.
The gyroscope chip might need to be reset to be used.
Without the chip being reset, the driver stopped at the first
regmap_read (to get the CHIP_ID) and failed to probe.
The datasheet of the gyroscope says that a minimum wait of 30ms after
the reset has to be done.
This patch has been checked on a BMX055 and the datasheet of the BMG160
and the BMI055 give the same reset register and bits.
Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/iio/gyro/bmg160_core.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
--- a/drivers/iio/gyro/bmg160_core.c
+++ b/drivers/iio/gyro/bmg160_core.c
@@ -28,6 +28,7 @@
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/regmap.h>
+#include <linux/delay.h>
#include "bmg160.h"
#define BMG160_IRQ_NAME "bmg160_event"
@@ -53,6 +54,9 @@
#define BMG160_NO_FILTER 0
#define BMG160_DEF_BW 100
+#define BMG160_GYRO_REG_RESET 0x14
+#define BMG160_GYRO_RESET_VAL 0xb6
+
#define BMG160_REG_INT_MAP_0 0x17
#define BMG160_INT_MAP_0_BIT_ANY BIT(1)
@@ -186,6 +190,14 @@ static int bmg160_chip_init(struct bmg16
int ret;
unsigned int val;
+ /*
+ * Reset chip to get it in a known good state. A delay of 30ms after
+ * reset is required according to the datasheet.
+ */
+ regmap_write(data->regmap, BMG160_GYRO_REG_RESET,
+ BMG160_GYRO_RESET_VAL);
+ usleep_range(30000, 30700);
+
ret = regmap_read(data->regmap, BMG160_REG_CHIP_ID, &val);
if (ret < 0) {
dev_err(data->dev, "Error reading reg_chip_id\n");
next prev parent reply other threads:[~2017-04-10 17:56 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-10 16:38 [PATCH 4.4 00/32] 4.4.61-stable review Greg Kroah-Hartman
2017-04-10 16:38 ` [PATCH 4.4 01/32] drm/vmwgfx: Type-check lookups of fence objects Greg Kroah-Hartman
2017-04-10 16:38 ` [PATCH 4.4 02/32] drm/vmwgfx: NULL pointer dereference in vmw_surface_define_ioctl() Greg Kroah-Hartman
2017-04-10 16:38 ` [PATCH 4.4 03/32] drm/vmwgfx: avoid calling vzalloc with a 0 size in vmw_get_cap_3d_ioctl() Greg Kroah-Hartman
2017-04-10 16:38 ` [PATCH 4.4 04/32] drm/ttm, drm/vmwgfx: Relax permission checking when opening surfaces Greg Kroah-Hartman
2017-04-10 16:38 ` [PATCH 4.4 05/32] drm/vmwgfx: Remove getparam error message Greg Kroah-Hartman
2017-04-10 16:38 ` [PATCH 4.4 06/32] drm/vmwgfx: fix integer overflow in vmw_surface_define_ioctl() Greg Kroah-Hartman
2017-04-10 16:38 ` [PATCH 4.4 07/32] sysfs: be careful of error returns from ops->show() Greg Kroah-Hartman
2017-04-10 16:38 ` [PATCH 4.4 08/32] staging: android: ashmem: lseek failed due to no FMODE_LSEEK Greg Kroah-Hartman
2017-04-10 16:38 ` [PATCH 4.4 09/32] arm/arm64: KVM: Take mmap_sem in stage2_unmap_vm Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 10/32] arm/arm64: KVM: Take mmap_sem in kvm_arch_prepare_memory_region Greg Kroah-Hartman
2017-04-10 16:39 ` Greg Kroah-Hartman [this message]
2017-04-10 16:39 ` [PATCH 4.4 12/32] Reset TreeId to zero on SMB2 TREE_CONNECT Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 13/32] ptrace: fix PTRACE_LISTEN race corrupting task->state Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 14/32] ring-buffer: Fix return value check in test_ringbuffer() Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 15/32] metag/usercopy: Drop unused macros Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 16/32] metag/usercopy: Fix alignment error checking Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 17/32] metag/usercopy: Add early abort to copy_to_user Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 18/32] metag/usercopy: Zero rest of buffer from copy_from_user Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 19/32] metag/usercopy: Set flags before ADDZ Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 20/32] metag/usercopy: Fix src fixup in from user rapf loops Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 21/32] metag/usercopy: Add missing fixups Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 22/32] powerpc/mm: Add missing global TLB invalidate if cxl is active Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 23/32] powerpc: Dont try to fix up misaligned load-with-reservation instructions Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 24/32] nios2: reserve boot memory for device tree Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 25/32] s390/decompressor: fix initrd corruption caused by bss clear Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 26/32] s390/uaccess: get_user() should zero on failure (again) Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 27/32] MIPS: Force o32 fp64 support on 32bit MIPS64r6 kernels Greg Kroah-Hartman
2017-04-14 23:45 ` Maciej W. Rozycki
2017-04-19 13:13 ` Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 28/32] MIPS: ralink: Fix typos in rt3883 pinctrl Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 29/32] MIPS: End spinlocks with .insn Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 30/32] MIPS: Lantiq: fix missing xbar kernel panic Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 31/32] MIPS: Flush wrong invalid FTLB entry for huge page Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 32/32] mm/mempolicy.c: fix error handling in set_mempolicy and mbind Greg Kroah-Hartman
2017-04-10 20:38 ` [PATCH 4.4 00/32] 4.4.61-stable review Shuah Khan
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