Re: [PATCH V6 06/21] clk: tegra: pll: Save and restore pll context

Sowjanya Komatineni
2019-07-22T03:22:37Z

On 7/21/19 3:21 PM, Dmitry Osipenko wrote:
> 21.07.2019 22:40, Sowjanya Komatineni пишет:
>> This patch implements save and restore of PLL context.
>>
>> During system suspend, core power goes off and looses the settings
>> of the Tegra CAR controller registers.
>>
>> So during suspend entry pll rate is stored and on resume it is
>> restored back along with its state.
>>
>> Acked-by: Thierry Reding <treding@nvidia.com>
>> Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
>> ---
>> drivers/clk/tegra/clk-pll.c | 121 ++++++++++++++++++++++++++++-----------
>> drivers/clk/tegra/clk-tegra210.c | 2 +-
>> drivers/clk/tegra/clk.h | 10 +++-
>> 3 files changed, 99 insertions(+), 34 deletions(-)
>>
>> diff --git a/drivers/clk/tegra/clk-pll.c b/drivers/clk/tegra/clk-pll.c
>> index 1583f5fc992f..f136964e6c44 100644
>> --- a/drivers/clk/tegra/clk-pll.c
>> +++ b/drivers/clk/tegra/clk-pll.c
>> @@ -1008,6 +1008,59 @@ static unsigned long clk_plle_recalc_rate(struct clk_hw *hw,
>> return rate;
>> }
>>
>> +void tegra_clk_sync_state_pll(struct clk_hw *hw)
>> +{
>> + if (!__clk_get_enable_count(hw->clk))
>> + clk_pll_disable(hw);
>> + else
>> + clk_pll_enable(hw);
>> +}
>> +
>> +static int tegra_clk_pll_save_context(struct clk_hw *hw)
>> +{
>> + struct tegra_clk_pll *pll = to_clk_pll(hw);
>> + u32 val = 0;
>> +
>> + pll->rate = clk_hw_get_rate(hw);
> Again, clk_hw_get_rate() returns cached value. Why do you need to
> duplicate it?
true, will remove storing in next version. thanks.
>> + if (pll->params->flags & TEGRA_PLLMB)
>> + val = pll_readl_base(pll);
>> + else if (pll->params->flags & TEGRA_PLLRE)
>> + val = pll_readl_base(pll) & divp_mask_shifted(pll);
>> +
>> + pll->pllbase_ctx = val;
>> +
>> + return 0;
>> +}
>> +
>> +static void tegra_clk_pll_restore_context(struct clk_hw *hw)
>> +{
>> + struct tegra_clk_pll *pll = to_clk_pll(hw);
>> + struct clk_hw *parent = clk_hw_get_parent(hw);
>> + unsigned long parent_rate = clk_hw_get_rate(parent);
>> + u32 val;
>> +
>> + if (clk_pll_is_enabled(hw))
>> + return;
>> +
>> + if (pll->params->flags & TEGRA_PLLMB) {
>> + pll_writel_base(pll->pllbase_ctx, pll);
>> + } else if (pll->params->flags & TEGRA_PLLRE) {
>> + val = pll_readl_base(pll);
>> + val &= ~(divp_mask_shifted(pll));
>> + pll_writel_base(pll->pllbase_ctx | val, pll);
>> + }
>> +
>> + if (pll->params->set_defaults)
>> + pll->params->set_defaults(pll);
>> +
>> + clk_pll_set_rate(hw, pll->rate, parent_rate);
>> +
>> + /* do not sync pllx state here. pllx is sync'd after dfll resume */
>> + if (!(pll->params->flags & TEGRA_PLLX))
>> + tegra_clk_sync_state_pll(hw);
>> +}
>> +
>> const struct clk_ops tegra_clk_pll_ops = {
>> .is_enabled = clk_pll_is_enabled,
>> .enable = clk_pll_enable,
>> @@ -1015,6 +1068,8 @@ const struct clk_ops tegra_clk_pll_ops = {
>> .recalc_rate = clk_pll_recalc_rate,
>> .round_rate = clk_pll_round_rate,
>> .set_rate = clk_pll_set_rate,
>> + .save_context = tegra_clk_pll_save_context,
>> + .restore_context = tegra_clk_pll_restore_context,
>> };
>>
>> const struct clk_ops tegra_clk_plle_ops = {
>> @@ -1802,6 +1857,27 @@ static int clk_pllu_tegra114_enable(struct clk_hw *hw)
>>
>> return ret;
>> }
>> +
>> +static void _clk_plle_tegra_init_parent(struct tegra_clk_pll *pll)
>> +{
>> + u32 val, val_aux;
>> +
>> + /* ensure parent is set to pll_ref */
>> + val = pll_readl_base(pll);
>> + val_aux = pll_readl(pll->params->aux_reg, pll);
>> +
>> + if (val & PLL_BASE_ENABLE) {
>> + if ((val_aux & PLLE_AUX_PLLRE_SEL) ||
>> + (val_aux & PLLE_AUX_PLLP_SEL))
>> + WARN(1, "pll_e enabled with unsupported parent %s\n",
>> + (val_aux & PLLE_AUX_PLLP_SEL) ? "pllp_out0" :
>> + "pll_re_vco");
>> + } else {
>> + val_aux &= ~(PLLE_AUX_PLLRE_SEL | PLLE_AUX_PLLP_SEL);
>> + pll_writel(val_aux, pll->params->aux_reg, pll);
>> + fence_udelay(1, pll->clk_base);
>> + }
>> +}
>> #endif
>>
>> static struct tegra_clk_pll *_tegra_init_pll(void __iomem *clk_base,
>> @@ -2214,27 +2290,12 @@ struct clk *tegra_clk_register_plle_tegra114(const char *name,
>> {
>> struct tegra_clk_pll *pll;
>> struct clk *clk;
>> - u32 val, val_aux;
>>
>> pll = _tegra_init_pll(clk_base, NULL, pll_params, lock);
>> if (IS_ERR(pll))
>> return ERR_CAST(pll);
>>
>> - /* ensure parent is set to pll_re_vco */
>> -
>> - val = pll_readl_base(pll);
>> - val_aux = pll_readl(pll_params->aux_reg, pll);
>> -
>> - if (val & PLL_BASE_ENABLE) {
>> - if ((val_aux & PLLE_AUX_PLLRE_SEL) ||
>> - (val_aux & PLLE_AUX_PLLP_SEL))
>> - WARN(1, "pll_e enabled with unsupported parent %s\n",
>> - (val_aux & PLLE_AUX_PLLP_SEL) ? "pllp_out0" :
>> - "pll_re_vco");
>> - } else {
>> - val_aux &= ~(PLLE_AUX_PLLRE_SEL | PLLE_AUX_PLLP_SEL);
>> - pll_writel(val_aux, pll_params->aux_reg, pll);
>> - }
>> + _clk_plle_tegra_init_parent(pll);
>>
>> clk = _tegra_clk_register_pll(pll, name, parent_name, flags,
>> &tegra_clk_plle_tegra114_ops);
>> @@ -2276,6 +2337,8 @@ static const struct clk_ops tegra_clk_pllss_ops = {
>> .recalc_rate = clk_pll_recalc_rate,
>> .round_rate = clk_pll_ramp_round_rate,
>> .set_rate = clk_pllxc_set_rate,
>> + .save_context = tegra_clk_pll_save_context,
>> + .restore_context = tegra_clk_pll_restore_context,
>> };
>>
>> struct clk *tegra_clk_register_pllss(const char *name, const char *parent_name,
>> @@ -2375,6 +2438,7 @@ struct clk *tegra_clk_register_pllre_tegra210(const char *name,
>> pll_params->vco_min = pll_params->adjust_vco(pll_params,
>> parent_rate);
>>
>> + pll_params->flags |= TEGRA_PLLRE;
>> pll = _tegra_init_pll(clk_base, pmc, pll_params, lock);
>> if (IS_ERR(pll))
>> return ERR_CAST(pll);
>> @@ -2520,11 +2584,19 @@ static void clk_plle_tegra210_disable(struct clk_hw *hw)
>> spin_unlock_irqrestore(pll->lock, flags);
>> }
>>
>> +static void tegra_clk_plle_t210_restore_context(struct clk_hw *hw)
>> +{
>> + struct tegra_clk_pll *pll = to_clk_pll(hw);
>> +
>> + _clk_plle_tegra_init_parent(pll);
>> +}
>> +
>> static const struct clk_ops tegra_clk_plle_tegra210_ops = {
>> .is_enabled = clk_plle_tegra210_is_enabled,
>> .enable = clk_plle_tegra210_enable,
>> .disable = clk_plle_tegra210_disable,
>> .recalc_rate = clk_pll_recalc_rate,
>> + .restore_context = tegra_clk_plle_t210_restore_context,
>> };
>>
>> struct clk *tegra_clk_register_plle_tegra210(const char *name,
>> @@ -2535,27 +2607,12 @@ struct clk *tegra_clk_register_plle_tegra210(const char *name,
>> {
>> struct tegra_clk_pll *pll;
>> struct clk *clk;
>> - u32 val, val_aux;
>>
>> pll = _tegra_init_pll(clk_base, NULL, pll_params, lock);
>> if (IS_ERR(pll))
>> return ERR_CAST(pll);
>>
>> - /* ensure parent is set to pll_re_vco */
>> -
>> - val = pll_readl_base(pll);
>> - val_aux = pll_readl(pll_params->aux_reg, pll);
>> -
>> - if (val & PLLE_BASE_ENABLE) {
>> - if ((val_aux & PLLE_AUX_PLLRE_SEL) ||
>> - (val_aux & PLLE_AUX_PLLP_SEL))
>> - WARN(1, "pll_e enabled with unsupported parent %s\n",
>> - (val_aux & PLLE_AUX_PLLP_SEL) ? "pllp_out0" :
>> - "pll_re_vco");
>> - } else {
>> - val_aux &= ~(PLLE_AUX_PLLRE_SEL | PLLE_AUX_PLLP_SEL);
>> - pll_writel(val_aux, pll_params->aux_reg, pll);
>> - }
>> + _clk_plle_tegra_init_parent(pll);
>>
>> clk = _tegra_clk_register_pll(pll, name, parent_name, flags,
>> &tegra_clk_plle_tegra210_ops);
>> diff --git a/drivers/clk/tegra/clk-tegra210.c b/drivers/clk/tegra/clk-tegra210.c
>> index 4721ee030d1c..58397f93166c 100644
>> --- a/drivers/clk/tegra/clk-tegra210.c
>> +++ b/drivers/clk/tegra/clk-tegra210.c
>> @@ -1602,7 +1602,7 @@ static struct tegra_clk_pll_params pll_x_params = {
>> .pdiv_tohw = pll_qlin_pdiv_to_hw,
>> .div_nmp = &pllx_nmp,
>> .freq_table = pll_x_freq_table,
>> - .flags = TEGRA_PLL_USE_LOCK | TEGRA_PLL_HAS_LOCK_ENABLE,
>> + .flags = TEGRA_PLL_USE_LOCK | TEGRA_PLL_HAS_LOCK_ENABLE | TEGRA_PLLX,
>> .dyn_ramp = tegra210_pllx_dyn_ramp,
>> .set_defaults = tegra210_pllx_set_defaults,
>> .calc_rate = tegra210_pll_fixed_mdiv_cfg,
>> diff --git a/drivers/clk/tegra/clk.h b/drivers/clk/tegra/clk.h
>> index fb29a8c27873..8532f5150091 100644
>> --- a/drivers/clk/tegra/clk.h
>> +++ b/drivers/clk/tegra/clk.h
>> @@ -235,6 +235,8 @@ struct tegra_clk_pll;
>> * TEGRA_PLLMB - PLLMB has should be treated similar to PLLM. This
>> * flag indicated that it is PLLMB.
>> * TEGRA_PLL_VCO_OUT - Used to indicate that the PLL has a VCO output
>> + * TEGRA_PLLRE - Used to indicate that it is PLLRE.
>> + * TEGRA_PLLX - Used to indicate that it is PLLX.
>> */
>> struct tegra_clk_pll_params {
>> unsigned long input_min;
>> @@ -301,6 +303,8 @@ struct tegra_clk_pll_params {
>> #define TEGRA_MDIV_NEW BIT(11)
>> #define TEGRA_PLLMB BIT(12)
>> #define TEGRA_PLL_VCO_OUT BIT(13)
>> +#define TEGRA_PLLRE BIT(14)
>> +#define TEGRA_PLLX BIT(15)
>>
>> /**
>> * struct tegra_clk_pll - Tegra PLL clock
>> @@ -310,6 +314,8 @@ struct tegra_clk_pll_params {
>> * @pmc: address of PMC, required to read override bits
>> * @lock: register lock
>> * @params: PLL parameters
>> + * @rate: rate during system suspend and resume
>> + * @pllbase_ctx: pll base register value during suspend and resume
>> */
>> struct tegra_clk_pll {
>> struct clk_hw hw;
>> @@ -317,6 +323,8 @@ struct tegra_clk_pll {
>> void __iomem *pmc;
>> spinlock_t *lock;
>> struct tegra_clk_pll_params *params;
>> + unsigned long rate;
>> + u32 pllbase_ctx;
>> };
>>
>> #define to_clk_pll(_hw) container_of(_hw, struct tegra_clk_pll, hw)
>> @@ -840,7 +848,7 @@ u16 tegra_pll_get_fixed_mdiv(struct clk_hw *hw, unsigned long input_rate);
>> int tegra_pll_p_div_to_hw(struct tegra_clk_pll *pll, u8 p_div);
>> int div_frac_get(unsigned long rate, unsigned parent_rate, u8 width,
>> u8 frac_width, u8 flags);
>> -
>> +void tegra_clk_sync_state_pll(struct clk_hw *hw);
>>
>> /* Combined read fence with delay */
>> #define fence_udelay(delay, reg) \
>>