From: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Date: Fri, 13 Jul 2018 15:20:17 +0000 (+0200)
Subject: i2c: davinci: Avoid zero value of CLKH
X-Git-Tag: v4.4.154~58
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=ca08b42d1f69d4af1037dbb0091120cc583c6d29;p=profile%2Fcommon%2Fplatform%2Fkernel%2Flinux-artik7.git

i2c: davinci: Avoid zero value of CLKH

[ Upstream commit cc8de9a68599b261244ea453b38678229f06ada7 ]

If CLKH is set to 0 I2C clock is not generated at all, so avoid this value
and stretch the clock in this case.

Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Acked-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index a8bdcb5..57f6eb1 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -234,12 +234,16 @@ static void i2c_davinci_calc_clk_dividers(struct davinci_i2c_dev *dev)
 	/*
 	 * It's not always possible to have 1 to 2 ratio when d=7, so fall back
 	 * to minimal possible clkh in this case.
+	 *
+	 * Note:
+	 * CLKH is not allowed to be 0, in this case I2C clock is not generated
+	 * at all
 	 */
-	if (clk >= clkl + d) {
+	if (clk > clkl + d) {
 		clkh = clk - clkl - d;
 		clkl -= d;
 	} else {
-		clkh = 0;
+		clkh = 1;
 		clkl = clk - (d << 1);
 	}