[PATCH AUTOSEL 5.0 251/262] clk: rockchip: fix frac settings of GPLL clock for rk3328

Sasha Levin
2019-03-27T19:13:38Z

From: Katsuhiro Suzuki <katsuhiro@katsuster.net>

[ Upstream commit a0e447b0c50240a90ab84b7126b3c06b0bab4adc ]

This patch fixes settings of GPLL frequency in fractional mode for
rk3328. In this mode, FOUTVCO is calcurated by following formula:
FOUTVCO = FREF * FBDIV / REFDIV + ((FREF * FRAC / REFDIV) >> 24)

The problem is in FREF * FRAC >> 24 term. This result always lacks
one from target value is specified by rate member. For example first
itme of rk3328_pll_frac_rate originally has
- rate : 1016064000
- refdiv: 3
- fbdiv : 127
- frac : 134217
- FREF * FBDIV / REFDIV = 1016000000
- (FREF * FRAC / REFDIV) >> 24 = 63999
Thus calculated rate is 1016063999. It seems wrong.

If frac has 134218 (it is increased 1 from original value), second
term is 64000. All other items have same situation. So this patch
adds 1 to frac member in all items of rk3328_pll_frac_rate.

Signed-off-by: Katsuhiro Suzuki <katsuhiro@katsuster.net>
Acked-by: Elaine Zhang <zhangqing@rock-chips.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/clk/rockchip/clk-rk3328.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/clk/rockchip/clk-rk3328.c b/drivers/clk/rockchip/clk-rk3328.c
index faa94adb2a37..65ab5c2f48b0 100644
--- a/drivers/clk/rockchip/clk-rk3328.c
+++ b/drivers/clk/rockchip/clk-rk3328.c
@@ -78,17 +78,17 @@ static struct rockchip_pll_rate_table rk3328_pll_rates[] = {

static struct rockchip_pll_rate_table rk3328_pll_frac_rates[] = {
/* _mhz, _refdiv, _fbdiv, _postdiv1, _postdiv2, _dsmpd, _frac */
- RK3036_PLL_RATE(1016064000, 3, 127, 1, 1, 0, 134217),
+ RK3036_PLL_RATE(1016064000, 3, 127, 1, 1, 0, 134218),
/* vco = 1016064000 */
- RK3036_PLL_RATE(983040000, 24, 983, 1, 1, 0, 671088),
+ RK3036_PLL_RATE(983040000, 24, 983, 1, 1, 0, 671089),
/* vco = 983040000 */
- RK3036_PLL_RATE(491520000, 24, 983, 2, 1, 0, 671088),
+ RK3036_PLL_RATE(491520000, 24, 983, 2, 1, 0, 671089),
/* vco = 983040000 */
- RK3036_PLL_RATE(61440000, 6, 215, 7, 2, 0, 671088),
+ RK3036_PLL_RATE(61440000, 6, 215, 7, 2, 0, 671089),
/* vco = 860156000 */
- RK3036_PLL_RATE(56448000, 12, 451, 4, 4, 0, 9797894),
+ RK3036_PLL_RATE(56448000, 12, 451, 4, 4, 0, 9797895),
/* vco = 903168000 */
- RK3036_PLL_RATE(40960000, 12, 409, 4, 5, 0, 10066329),
+ RK3036_PLL_RATE(40960000, 12, 409, 4, 5, 0, 10066330),
/* vco = 819200000 */
{ /* sentinel */ },
};
--
2.19.1