| From foo@baz Sun Aug 26 09:13:00 CEST 2018 |
| From: Alexander Sverdlin <alexander.sverdlin@nokia.com> |
| Date: Fri, 13 Jul 2018 17:20:17 +0200 |
| Subject: i2c: davinci: Avoid zero value of CLKH |
| |
| From: Alexander Sverdlin <alexander.sverdlin@nokia.com> |
| |
| [ 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> |
| --- |
| drivers/i2c/busses/i2c-davinci.c | 8 ++++++-- |
| 1 file changed, 6 insertions(+), 2 deletions(-) |
| |
| --- a/drivers/i2c/busses/i2c-davinci.c |
| +++ b/drivers/i2c/busses/i2c-davinci.c |
| @@ -234,12 +234,16 @@ static void i2c_davinci_calc_clk_divider |
| /* |
| * 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); |
| } |
| |
