i2c: davinci: Avoid zero value of CLKH

BugLink: https://bugs.launchpad.net/bugs/1792392

[ Upstream commit cc8de9a6 ]

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>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

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);
 	}