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In-Reply-To: <20180425142209.30745-1-heikki.krogerus@linux.intel.com>
From:   Nikolaus Voss <nv@vosn.de>
To:     Heikki Krogerus <heikki.krogerus@linux.intel.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Guenter Roeck <linux@roeck-us.net>
Cc:     linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        nikolaus.voss@loewensteinmedical.de
Date:   Mon, 10 Sep 2018 07:05:01 +0200
Subject: [PATCH] usb: typec: tps6598x: handle block writes separately with
 plain-I2C adapters
Message-Id: <20190220110017.BFA344CE86@mail.steuer-voss.de>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Commit 1a2f474d328f handles block _reads_ separately with plain-I2C
adapters, but the problem described with regmap-i2c not handling
SMBus block transfers (i.e. read and writes) correctly also exists
with writes.

As workaround, this patch adds a block write function the same way
1a2f474d328f adds a block read function.

Fixes: 1a2f474d328f ("usb: typec: tps6598x: handle block reads separately with plain-I2C adapters")
Fixes: 0a4c005bd171 ("usb: typec: driver for TI TPS6598x USB Power Delivery controllers")
Signed-off-by: Nikolaus Voss <nikolaus.voss@loewensteinmedical.de>
---
 drivers/usb/typec/tps6598x.c | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/typec/tps6598x.c b/drivers/usb/typec/tps6598x.c
index c84c8c189e90..57a3e6c5c175 100644
--- a/drivers/usb/typec/tps6598x.c
+++ b/drivers/usb/typec/tps6598x.c
@@ -110,6 +110,20 @@ tps6598x_block_read(struct tps6598x *tps, u8 reg, void *val, size_t len)
 	return 0;
 }
 
+static int tps6598x_block_write(struct tps6598x *tps, u8 reg,
+				void *val, size_t len)
+{
+	u8 data[len + 1];
+
+	if (!tps->i2c_protocol)
+		return regmap_raw_write(tps->regmap, reg, val, len);
+
+	data[0] = len;
+	memcpy(&data[1], val, len);
+
+	return regmap_raw_write(tps->regmap, reg, data, sizeof(data));
+}
+
 static inline int tps6598x_read16(struct tps6598x *tps, u8 reg, u16 *val)
 {
 	return tps6598x_block_read(tps, reg, val, sizeof(u16));
@@ -127,23 +141,23 @@ static inline int tps6598x_read64(struct tps6598x *tps, u8 reg, u64 *val)
 
 static inline int tps6598x_write16(struct tps6598x *tps, u8 reg, u16 val)
 {
-	return regmap_raw_write(tps->regmap, reg, &val, sizeof(u16));
+	return tps6598x_block_write(tps, reg, &val, sizeof(u16));
 }
 
 static inline int tps6598x_write32(struct tps6598x *tps, u8 reg, u32 val)
 {
-	return regmap_raw_write(tps->regmap, reg, &val, sizeof(u32));
+	return tps6598x_block_write(tps, reg, &val, sizeof(u32));
 }
 
 static inline int tps6598x_write64(struct tps6598x *tps, u8 reg, u64 val)
 {
-	return regmap_raw_write(tps->regmap, reg, &val, sizeof(u64));
+	return tps6598x_block_write(tps, reg, &val, sizeof(u64));
 }
 
 static inline int
 tps6598x_write_4cc(struct tps6598x *tps, u8 reg, const char *val)
 {
-	return regmap_raw_write(tps->regmap, reg, &val, sizeof(u32));
+	return tps6598x_block_write(tps, reg, &val, sizeof(u32));
 }
 
 static int tps6598x_read_partner_identity(struct tps6598x *tps)
-- 
2.17.1