From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Sun, 16 Oct 2022 07:28:07 +0000 (+0200)
Subject: 4.9-stable patches
X-Git-Tag: v5.4.219~177
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=1e6749740b4b75aed0973822c10d94db5b82825e;p=thirdparty%2Fkernel%2Fstable-queue.git

4.9-stable patches

added patches:
	iio-dac-ad5593r-fix-i2c-read-protocol-requirements.patch
---

diff --git a/queue-4.9/iio-dac-ad5593r-fix-i2c-read-protocol-requirements.patch b/queue-4.9/iio-dac-ad5593r-fix-i2c-read-protocol-requirements.patch
new file mode 100644
index 00000000000..b4088dfa9b8
--- /dev/null
+++ b/queue-4.9/iio-dac-ad5593r-fix-i2c-read-protocol-requirements.patch
@@ -0,0 +1,113 @@
+From 558a25f903b4af6361b7fbeea08a6446a0745653 Mon Sep 17 00:00:00 2001
+From: Michael Hennerich <michael.hennerich@analog.com>
+Date: Tue, 13 Sep 2022 09:34:12 +0200
+Subject: iio: dac: ad5593r: Fix i2c read protocol requirements
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+From: Michael Hennerich <michael.hennerich@analog.com>
+
+commit 558a25f903b4af6361b7fbeea08a6446a0745653 upstream.
+
+For reliable operation across the full range of supported
+interface rates, the AD5593R needs a STOP condition between
+address write, and data read (like show in the datasheet Figure 40)
+so in turn i2c_smbus_read_word_swapped cannot be used.
+
+While at it, a simple helper was added to make the code simpler.
+
+Fixes: 56ca9db862bf ("iio: dac: Add support for the AD5592R/AD5593R ADCs/DACs")
+Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
+Signed-off-by: Nuno Sá <nuno.sa@analog.com>
+Cc: <Stable@vger.kernel.org>
+Link: https://lore.kernel.org/r/20220913073413.140475-2-nuno.sa@analog.com
+Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/iio/dac/ad5593r.c |   46 +++++++++++++++++++++++++++-------------------
+ 1 file changed, 27 insertions(+), 19 deletions(-)
+
+--- a/drivers/iio/dac/ad5593r.c
++++ b/drivers/iio/dac/ad5593r.c
+@@ -14,6 +14,8 @@
+ #include <linux/module.h>
+ #include <linux/of.h>
+ 
++#include <asm/unaligned.h>
++
+ #define AD5593R_MODE_CONF		(0 << 4)
+ #define AD5593R_MODE_DAC_WRITE		(1 << 4)
+ #define AD5593R_MODE_ADC_READBACK	(4 << 4)
+@@ -21,6 +23,24 @@
+ #define AD5593R_MODE_GPIO_READBACK	(6 << 4)
+ #define AD5593R_MODE_REG_READBACK	(7 << 4)
+ 
++static int ad5593r_read_word(struct i2c_client *i2c, u8 reg, u16 *value)
++{
++	int ret;
++	u8 buf[2];
++
++	ret = i2c_smbus_write_byte(i2c, reg);
++	if (ret < 0)
++		return ret;
++
++	ret = i2c_master_recv(i2c, buf, sizeof(buf));
++	if (ret < 0)
++		return ret;
++
++	*value = get_unaligned_be16(buf);
++
++	return 0;
++}
++
+ static int ad5593r_write_dac(struct ad5592r_state *st, unsigned chan, u16 value)
+ {
+ 	struct i2c_client *i2c = to_i2c_client(st->dev);
+@@ -39,13 +59,7 @@ static int ad5593r_read_adc(struct ad559
+ 	if (val < 0)
+ 		return (int) val;
+ 
+-	val = i2c_smbus_read_word_swapped(i2c, AD5593R_MODE_ADC_READBACK);
+-	if (val < 0)
+-		return (int) val;
+-
+-	*value = (u16) val;
+-
+-	return 0;
++	return ad5593r_read_word(i2c, AD5593R_MODE_ADC_READBACK, value);
+ }
+ 
+ static int ad5593r_reg_write(struct ad5592r_state *st, u8 reg, u16 value)
+@@ -59,25 +73,19 @@ static int ad5593r_reg_write(struct ad55
+ static int ad5593r_reg_read(struct ad5592r_state *st, u8 reg, u16 *value)
+ {
+ 	struct i2c_client *i2c = to_i2c_client(st->dev);
+-	s32 val;
+-
+-	val = i2c_smbus_read_word_swapped(i2c, AD5593R_MODE_REG_READBACK | reg);
+-	if (val < 0)
+-		return (int) val;
+ 
+-	*value = (u16) val;
+-
+-	return 0;
++	return ad5593r_read_word(i2c, AD5593R_MODE_REG_READBACK | reg, value);
+ }
+ 
+ static int ad5593r_gpio_read(struct ad5592r_state *st, u8 *value)
+ {
+ 	struct i2c_client *i2c = to_i2c_client(st->dev);
+-	s32 val;
++	u16 val;
++	int ret;
+ 
+-	val = i2c_smbus_read_word_swapped(i2c, AD5593R_MODE_GPIO_READBACK);
+-	if (val < 0)
+-		return (int) val;
++	ret = ad5593r_read_word(i2c, AD5593R_MODE_GPIO_READBACK, &val);
++	if (ret)
++		return ret;
+ 
+ 	*value = (u8) val;
+ 
diff --git a/queue-4.9/series b/queue-4.9/series
index e8225e91911..984c05e23ff 100644
--- a/queue-4.9/series
+++ b/queue-4.9/series
@@ -42,3 +42,4 @@ alsa-oss-fix-potential-deadlock-at-unregistration.patch
 alsa-rawmidi-drop-register_mutex-in-snd_rawmidi_free.patch
 alsa-usb-audio-fix-potential-memory-leaks.patch
 alsa-usb-audio-fix-null-dererence-at-error-path.patch
+iio-dac-ad5593r-fix-i2c-read-protocol-requirements.patch