linux-stable/drivers/clk/rockchip
Sascha Hauer 6931f85c29 clk: rockchip: Mark hclk_vo as critical on rk3568
Whenever pclk_vo is enabled hclk_vo must be enabled as well. This is
described in the Reference Manual as:

| 2.8.6 NIU Clock gating reliance
|
| A part of niu clocks have a dependence on another niu clock in order to
| sharing the internal bus. When these clocks are in use, another niu
| clock must be opened, and cannot be gated.  These clocks and the special
| clock on which they are relied are as following:
|
| Clocks which have dependency     The clock which can not be gated
| -----------------------------------------------------------------
| ...
| pclk_vo_niu, hclk_vo_s_niu       hclk_vo_niu
| ...

The clock framework doesn't offer a way to enable clock B whenever clock A is
enabled, at least not when B is not an ancestor of A. Workaround this by
marking hclk_vo as critical so it is never disabled. This is suboptimal in
terms of power consumption, but a stop gap solution until the clock framework
has a way to deal with this.

We have this clock tree:

|      aclk_vo                  2        2        0   300000000          0     0  50000         Y
|         aclk_hdcp             0        0        0   300000000          0     0  50000         N
|         pclk_vo               2        3        0    75000000          0     0  50000         Y
|            pclk_edp_ctrl      0        0        0    75000000          0     0  50000         N
|            pclk_dsitx_1       0        0        0    75000000          0     0  50000         N
|            pclk_dsitx_0       1        2        0    75000000          0     0  50000         Y
|            pclk_hdmi_host     1        2        0    75000000          0     0  50000         Y
|            pclk_hdcp          0        0        0    75000000          0     0  50000         N
|         hclk_vo               2        5        0   150000000          0     0  50000         Y
|            hclk_hdcp          0        0        0   150000000          0     0  50000         N
|            hclk_vop           0        2        0   150000000          0     0  50000         N

Without this patch the edp, dsitx, hdmi and hdcp driver would enable their
clocks which then enables pclk_vo, but hclk_vo stays disabled and register
accesses just hang. hclk_vo is enabled by the VOP2 driver, so reproducibility
of this issue depends on the probe order.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Michael Riesch <michael.riesch@wolfvision.net>
Link: https://lore.kernel.org/r/20220422072841.2206452-2-s.hauer@pengutronix.de
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
2022-05-03 11:16:48 +02:00
..
clk-cpu.c clk: rockchip: support more core div setting 2021-03-21 11:10:58 +01:00
clk-ddr.c clk: rockchip: Export rockchip_clk_register_ddrclk() 2020-09-22 15:16:37 +02:00
clk-half-divider.c clk: rockchip: Demote non-conformant kernel-doc header in half-divider 2021-01-26 00:24:05 +01:00
clk-inverter.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00
clk-mmc-phase.c clk: rockchip: fix mmc get phase 2020-03-06 12:06:01 -08:00
clk-muxgrf.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282 2019-06-05 17:36:37 +02:00
clk-pll.c clk: rockchip: drop GRF dependency for rk3328/rk3036 pll types 2021-07-29 11:22:29 +02:00
clk-px30.c clk: rockchip: support more core div setting 2021-03-21 11:10:58 +01:00
clk-rk3036.c clk: rockchip: Add support for hclk_sfc on rk3036 2021-07-16 00:33:42 +02:00
clk-rk3128.c clk: rockchip: support more core div setting 2021-03-21 11:10:58 +01:00
clk-rk3188.c clk: rockchip: support more core div setting 2021-03-21 11:10:58 +01:00
clk-rk3228.c clk: rockchip: support more core div setting 2021-03-21 11:10:58 +01:00
clk-rk3288.c clk: rockchip: support more core div setting 2021-03-21 11:10:58 +01:00
clk-rk3308.c clk: rockchip: make rk3308 ddrphy4x clock critical 2021-07-29 12:43:11 +02:00
clk-rk3328.c clk: rockchip: support more core div setting 2021-03-21 11:10:58 +01:00
clk-rk3368.c clk: rockchip: support more core div setting 2021-03-21 11:10:58 +01:00
clk-rk3399.c clk: rockchip: drop module parts from rk3399 and rk3568 drivers 2021-11-02 17:59:00 -07:00
clk-rk3568.c clk: rockchip: Mark hclk_vo as critical on rk3568 2022-05-03 11:16:48 +02:00
clk-rv1108.c clk: rockchip: support more core div setting 2021-03-21 11:10:58 +01:00
clk.c clk: rockchip: re-add rational best approximation algorithm to the fractional divider 2022-02-24 00:07:16 +01:00
clk.h clk: rockchip: Optimize PLL table memory usage 2021-05-11 12:22:29 +02:00
Kconfig clk: rockchip: drop module parts from rk3399 and rk3568 drivers 2021-11-02 17:59:00 -07:00
Makefile clk: rockchip: add clock controller for rk3568 2021-03-21 11:10:59 +01:00
softrst.c clk: rockchip: Export rockchip_register_softrst() 2020-09-22 15:16:38 +02:00