Re: [PATCH 2/4] clk: meson: meson8b: Fix the polarity of the RESET_N lines

From: Jerome Brunet
Date: Thu Apr 16 2020 - 06:41:03 EST



On Tue 14 Apr 2020 at 22:00, Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx> wrote:

> CLKC_RESET_VID_DIVIDER_CNTL_RESET_N_POST and
> CLKC_RESET_VID_DIVIDER_CNTL_RESET_N_PRE are active low. This means:
> - asserting them requires setting the register value to 0
> - de-asserting them requires setting the register value to 1
>
> Set the register value accordingly for these two reset lines by setting
> the inverted the register value compared to all other reset lines.
>
> Fixes: 189621726bc2f6 ("clk: meson: meson8b: register the built-in reset controller")
> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
> ---
> drivers/clk/meson/meson8b.c | 81 ++++++++++++++++++++++++++-----------
> 1 file changed, 58 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/clk/meson/meson8b.c b/drivers/clk/meson/meson8b.c
> index 90d284ffc780..fa251e45e208 100644
> --- a/drivers/clk/meson/meson8b.c
> +++ b/drivers/clk/meson/meson8b.c
> @@ -3506,54 +3506,87 @@ static struct clk_regmap *const meson8b_clk_regmaps[] = {
> static const struct meson8b_clk_reset_line {
> u32 reg;
> u8 bit_idx;
> + bool active_low;
> } meson8b_clk_reset_bits[] = {
> [CLKC_RESET_L2_CACHE_SOFT_RESET] = {
> - .reg = HHI_SYS_CPU_CLK_CNTL0, .bit_idx = 30
> + .reg = HHI_SYS_CPU_CLK_CNTL0,
> + .bit_idx = 30,
> + .active_low = false,
> },
> [CLKC_RESET_AXI_64_TO_128_BRIDGE_A5_SOFT_RESET] = {
> - .reg = HHI_SYS_CPU_CLK_CNTL0, .bit_idx = 29
> + .reg = HHI_SYS_CPU_CLK_CNTL0,
> + .bit_idx = 29,
> + .active_low = false,
> },
> [CLKC_RESET_SCU_SOFT_RESET] = {
> - .reg = HHI_SYS_CPU_CLK_CNTL0, .bit_idx = 28
> + .reg = HHI_SYS_CPU_CLK_CNTL0,
> + .bit_idx = 28,
> + .active_low = false,
> },
> [CLKC_RESET_CPU3_SOFT_RESET] = {
> - .reg = HHI_SYS_CPU_CLK_CNTL0, .bit_idx = 27
> + .reg = HHI_SYS_CPU_CLK_CNTL0,
> + .bit_idx = 27,
> + .active_low = false,
> },
> [CLKC_RESET_CPU2_SOFT_RESET] = {
> - .reg = HHI_SYS_CPU_CLK_CNTL0, .bit_idx = 26
> + .reg = HHI_SYS_CPU_CLK_CNTL0,
> + .bit_idx = 26,
> + .active_low = false,
> },
> [CLKC_RESET_CPU1_SOFT_RESET] = {
> - .reg = HHI_SYS_CPU_CLK_CNTL0, .bit_idx = 25
> + .reg = HHI_SYS_CPU_CLK_CNTL0,
> + .bit_idx = 25,
> + .active_low = false,
> },
> [CLKC_RESET_CPU0_SOFT_RESET] = {
> - .reg = HHI_SYS_CPU_CLK_CNTL0, .bit_idx = 24
> + .reg = HHI_SYS_CPU_CLK_CNTL0,
> + .bit_idx = 24,
> + .active_low = false,
> },
> [CLKC_RESET_A5_GLOBAL_RESET] = {
> - .reg = HHI_SYS_CPU_CLK_CNTL0, .bit_idx = 18
> + .reg = HHI_SYS_CPU_CLK_CNTL0,
> + .bit_idx = 18,
> + .active_low = false,
> },
> [CLKC_RESET_A5_AXI_SOFT_RESET] = {
> - .reg = HHI_SYS_CPU_CLK_CNTL0, .bit_idx = 17
> + .reg = HHI_SYS_CPU_CLK_CNTL0,
> + .bit_idx = 17,
> + .active_low = false,
> },
> [CLKC_RESET_A5_ABP_SOFT_RESET] = {
> - .reg = HHI_SYS_CPU_CLK_CNTL0, .bit_idx = 16
> + .reg = HHI_SYS_CPU_CLK_CNTL0,
> + .bit_idx = 16,
> + .active_low = false,
> },
> [CLKC_RESET_AXI_64_TO_128_BRIDGE_MMC_SOFT_RESET] = {
> - .reg = HHI_SYS_CPU_CLK_CNTL1, .bit_idx = 30
> + .reg = HHI_SYS_CPU_CLK_CNTL1,
> + .bit_idx = 30,
> + .active_low = false,
> },
> [CLKC_RESET_VID_CLK_CNTL_SOFT_RESET] = {
> - .reg = HHI_VID_CLK_CNTL, .bit_idx = 15
> + .reg = HHI_VID_CLK_CNTL,
> + .bit_idx = 15,
> + .active_low = false,
> },
> [CLKC_RESET_VID_DIVIDER_CNTL_SOFT_RESET_POST] = {
> - .reg = HHI_VID_DIVIDER_CNTL, .bit_idx = 7
> + .reg = HHI_VID_DIVIDER_CNTL,
> + .bit_idx = 7,
> + .active_low = false,
> },
> [CLKC_RESET_VID_DIVIDER_CNTL_SOFT_RESET_PRE] = {
> - .reg = HHI_VID_DIVIDER_CNTL, .bit_idx = 3
> + .reg = HHI_VID_DIVIDER_CNTL,
> + .bit_idx = 3,
> + .active_low = false,
> },
> [CLKC_RESET_VID_DIVIDER_CNTL_RESET_N_POST] = {
> - .reg = HHI_VID_DIVIDER_CNTL, .bit_idx = 1
> + .reg = HHI_VID_DIVIDER_CNTL,
> + .bit_idx = 1,
> + .active_low = true,
> },
> [CLKC_RESET_VID_DIVIDER_CNTL_RESET_N_PRE] = {
> - .reg = HHI_VID_DIVIDER_CNTL, .bit_idx = 0
> + .reg = HHI_VID_DIVIDER_CNTL,
> + .bit_idx = 0,
> + .active_low = true,
> },
> };
>
> @@ -3562,22 +3595,24 @@ static int meson8b_clk_reset_update(struct reset_controller_dev *rcdev,
> {
> struct meson8b_clk_reset *meson8b_clk_reset =
> container_of(rcdev, struct meson8b_clk_reset, reset);
> - unsigned long flags;
> const struct meson8b_clk_reset_line *reset;
> + unsigned long flags;
> + unsigned int value;

suggestion:

unsigned int value = 0;

>
> if (id >= ARRAY_SIZE(meson8b_clk_reset_bits))
> return -EINVAL;
>
> reset = &meson8b_clk_reset_bits[id];
>
> + if (assert == reset->active_low)
> + value = 0;
> + else
> + value = BIT(reset->bit_idx);

if (assert ^ reset->active_low)
value = BIT(reset->bit_idx);

?

> +
> spin_lock_irqsave(&meson_clk_lock, flags);
>
> - if (assert)
> - regmap_update_bits(meson8b_clk_reset->regmap, reset->reg,
> - BIT(reset->bit_idx), BIT(reset->bit_idx));
> - else
> - regmap_update_bits(meson8b_clk_reset->regmap, reset->reg,
> - BIT(reset->bit_idx), 0);
> + regmap_update_bits(meson8b_clk_reset->regmap, reset->reg,
> + BIT(reset->bit_idx), value);
>
> spin_unlock_irqrestore(&meson_clk_lock, flags);