This is a note to let you know that I've just added the patch titled clk: qcom: gdsc: Add support to update GDSC transition delay to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: clk-qcom-gdsc-add-support-to-update-gdsc-transition-.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit c474e6a72a80ee7d3fd2be6015902ed780c60180 Author: Taniya Das <tdas@xxxxxxxxxxxxxx> Date: Thu Feb 24 00:26:05 2022 +0530 clk: qcom: gdsc: Add support to update GDSC transition delay [ Upstream commit 4e7c4d3652f96f41179aab3ff53025c7a550d689 ] GDSCs have multiple transition delays which are used for the GDSC FSM states. Older targets/designs required these values to be updated from gdsc code to certain default values for the FSM state to work as expected. But on the newer targets/designs the values updated from the GDSC driver can hamper the FSM state to not work as expected. On SC7180 we observe black screens because the gdsc is being enabled/disabled very rapidly and the GDSC FSM state does not work as expected. This is due to the fact that the GDSC reset value is being updated from SW. Thus add support to update the transition delay from the clock controller gdscs as required. Fixes: 45dd0e55317cc ("clk: qcom: Add support for GDSCs) Signed-off-by: Taniya Das <tdas@xxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20220223185606.3941-1-tdas@xxxxxxxxxxxxxx Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx> Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/clk/qcom/gdsc.c b/drivers/clk/qcom/gdsc.c index a250f59708d8..888965bb93ed 100644 --- a/drivers/clk/qcom/gdsc.c +++ b/drivers/clk/qcom/gdsc.c @@ -1,6 +1,6 @@ // SPDX-License-Identifier: GPL-2.0-only /* - * Copyright (c) 2015, 2017-2018, The Linux Foundation. All rights reserved. + * Copyright (c) 2015, 2017-2018, 2022, The Linux Foundation. All rights reserved. */ #include <linux/bitops.h> @@ -31,9 +31,14 @@ #define CFG_GDSCR_OFFSET 0x4 /* Wait 2^n CXO cycles between all states. Here, n=2 (4 cycles). */ -#define EN_REST_WAIT_VAL (0x2 << 20) -#define EN_FEW_WAIT_VAL (0x8 << 16) -#define CLK_DIS_WAIT_VAL (0x2 << 12) +#define EN_REST_WAIT_VAL 0x2 +#define EN_FEW_WAIT_VAL 0x8 +#define CLK_DIS_WAIT_VAL 0x2 + +/* Transition delay shifts */ +#define EN_REST_WAIT_SHIFT 20 +#define EN_FEW_WAIT_SHIFT 16 +#define CLK_DIS_WAIT_SHIFT 12 #define RETAIN_MEM BIT(14) #define RETAIN_PERIPH BIT(13) @@ -308,7 +313,18 @@ static int gdsc_init(struct gdsc *sc) */ mask = HW_CONTROL_MASK | SW_OVERRIDE_MASK | EN_REST_WAIT_MASK | EN_FEW_WAIT_MASK | CLK_DIS_WAIT_MASK; - val = EN_REST_WAIT_VAL | EN_FEW_WAIT_VAL | CLK_DIS_WAIT_VAL; + + if (!sc->en_rest_wait_val) + sc->en_rest_wait_val = EN_REST_WAIT_VAL; + if (!sc->en_few_wait_val) + sc->en_few_wait_val = EN_FEW_WAIT_VAL; + if (!sc->clk_dis_wait_val) + sc->clk_dis_wait_val = CLK_DIS_WAIT_VAL; + + val = sc->en_rest_wait_val << EN_REST_WAIT_SHIFT | + sc->en_few_wait_val << EN_FEW_WAIT_SHIFT | + sc->clk_dis_wait_val << CLK_DIS_WAIT_SHIFT; + ret = regmap_update_bits(sc->regmap, sc->gdscr, mask, val); if (ret) return ret; diff --git a/drivers/clk/qcom/gdsc.h b/drivers/clk/qcom/gdsc.h index 64cdc8cf0d4d..907396ccb83f 100644 --- a/drivers/clk/qcom/gdsc.h +++ b/drivers/clk/qcom/gdsc.h @@ -1,6 +1,6 @@ /* SPDX-License-Identifier: GPL-2.0-only */ /* - * Copyright (c) 2015, 2017-2018, The Linux Foundation. All rights reserved. + * Copyright (c) 2015, 2017-2018, 2022, The Linux Foundation. All rights reserved. */ #ifndef __QCOM_GDSC_H__ @@ -21,6 +21,9 @@ struct reset_controller_dev; * @cxcs: offsets of branch registers to toggle mem/periph bits in * @cxc_count: number of @cxcs * @pwrsts: Possible powerdomain power states + * @en_rest_wait_val: transition delay value for receiving enr ack signal + * @en_few_wait_val: transition delay value for receiving enf ack signal + * @clk_dis_wait_val: transition delay value for halting clock * @resets: ids of resets associated with this gdsc * @reset_count: number of @resets * @rcdev: reset controller @@ -34,6 +37,9 @@ struct gdsc { unsigned int clamp_io_ctrl; unsigned int *cxcs; unsigned int cxc_count; + unsigned int en_rest_wait_val; + unsigned int en_few_wait_val; + unsigned int clk_dis_wait_val; const u8 pwrsts; /* Powerdomain allowable state bitfields */ #define PWRSTS_OFF BIT(0)