Re: [PATCH V6 09/21] clk: tegra: clk-super: Fix to enable PLLP branches to CPU

Sowjanya Komatineni
2019-07-21T22:39:20Z

On 7/21/19 2:16 PM, Dmitry Osipenko wrote:
> 21.07.2019 22:40, Sowjanya Komatineni пишет:
>> This patch has a fix to enable PLLP branches to CPU before changing
>> the CPU clusters clock source to PLLP for Gen5 Super clock.
>>
>> During system suspend entry and exit, CPU source will be switched
>> to PLLP and this needs PLLP branches to be enabled to CPU prior to
>> the switch.
>>
>> On system resume, warmboot code enables PLLP branches to CPU and
>> powers up the CPU with PLLP clock source.
>>
>> Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
>> ---
>> drivers/clk/tegra/clk-super.c | 11 +++++++++++
>> drivers/clk/tegra/clk-tegra-super-gen4.c | 4 ++--
>> drivers/clk/tegra/clk.h | 4 ++++
>> 3 files changed, 17 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/clk/tegra/clk-super.c b/drivers/clk/tegra/clk-super.c
>> index 39ef31b46df5..d73c587e4853 100644
>> --- a/drivers/clk/tegra/clk-super.c
>> +++ b/drivers/clk/tegra/clk-super.c
>> @@ -28,6 +28,9 @@
>> #define super_state_to_src_shift(m, s) ((m->width * s))
>> #define super_state_to_src_mask(m) (((1 << m->width) - 1))
>>
>> +#define CCLK_SRC_PLLP_OUT0 4
>> +#define CCLK_SRC_PLLP_OUT4 5
>> +
>> static u8 clk_super_get_parent(struct clk_hw *hw)
>> {
>> struct tegra_clk_super_mux *mux = to_clk_super_mux(hw);
>> @@ -97,6 +100,14 @@ static int clk_super_set_parent(struct clk_hw *hw, u8 index)
>> if (index == mux->div2_index)
>> index = mux->pllx_index;
>> }
>> +
>> + /*
>> + * Enable PLLP branches to CPU before selecting PLLP source
>> + */
>> + if ((mux->flags & TEGRA_CPU_CLK) &&
>> + ((index == CCLK_SRC_PLLP_OUT0) || (index == CCLK_SRC_PLLP_OUT4)))
>> + tegra_clk_set_pllp_out_cpu(true);
> Should somewhere here be tegra_clk_set_pllp_out_cpu(false) when
> switching from PLLP?
PLLP may be used for other CPU clusters.
>> val &= ~((super_state_to_src_mask(mux)) << shift);
>> val |= (index & (super_state_to_src_mask(mux))) << shift;
>>
>> diff --git a/drivers/clk/tegra/clk-tegra-super-gen4.c b/drivers/clk/tegra/clk-tegra-super-gen4.c
>> index cdfe7c9697e1..cd208d0eca2a 100644
>> --- a/drivers/clk/tegra/clk-tegra-super-gen4.c
>> +++ b/drivers/clk/tegra/clk-tegra-super-gen4.c
>> @@ -180,7 +180,7 @@ static void __init tegra_super_clk_init(void __iomem *clk_base,
>> gen_info->num_cclk_g_parents,
>> CLK_SET_RATE_PARENT,
>> clk_base + CCLKG_BURST_POLICY,
>> - 0, 4, 8, 0, NULL);
>> + TEGRA_CPU_CLK, 4, 8, 0, NULL);
>> } else {
>> clk = tegra_clk_register_super_mux("cclk_g",
>> gen_info->cclk_g_parents,
>> @@ -201,7 +201,7 @@ static void __init tegra_super_clk_init(void __iomem *clk_base,
>> gen_info->num_cclk_lp_parents,
>> CLK_SET_RATE_PARENT,
>> clk_base + CCLKLP_BURST_POLICY,
>> - 0, 4, 8, 0, NULL);
>> + TEGRA_CPU_CLK, 4, 8, 0, NULL);
>> } else {
>> clk = tegra_clk_register_super_mux("cclk_lp",
>> gen_info->cclk_lp_parents,
>> diff --git a/drivers/clk/tegra/clk.h b/drivers/clk/tegra/clk.h
>> index ac6de3a0b91f..c357b49e49b0 100644
>> --- a/drivers/clk/tegra/clk.h
>> +++ b/drivers/clk/tegra/clk.h
>> @@ -694,6 +694,9 @@ struct clk *tegra_clk_register_periph_data(void __iomem *clk_base,
>> * Flags:
>> * TEGRA_DIVIDER_2 - LP cluster has additional divider. This flag indicates
>> * that this is LP cluster clock.
>> + * TEGRA_CPU_CLK - This flag indicates this is CPU cluster clock. To use PLLP
>> + * for CPU clock source, need to enable PLLP branches to CPU by setting the
>> + * additional bit PLLP_OUT_CPU for gen5 super clock.
>> */
>> struct tegra_clk_super_mux {
>> struct clk_hw hw;
>> @@ -710,6 +713,7 @@ struct tegra_clk_super_mux {
>> #define to_clk_super_mux(_hw) container_of(_hw, struct tegra_clk_super_mux, hw)
>>
>> #define TEGRA_DIVIDER_2 BIT(0)
>> +#define TEGRA_CPU_CLK BIT(1)
> I'd name this TEGRA210_CPU_CLK for clarity.
>
>> extern const struct clk_ops tegra_clk_super_ops;
>> struct clk *tegra_clk_register_super_mux(const char *name,
>>
> Will be better to move the tegra_clk_set_pllp_out_cpu() definition into
> this patch, otherwise this looks inconsistent for reviewer.
ok, Will move to this patch