On Tue, Jun 18, 2019 at 12:46:22AM -0700, Sowjanya Komatineni wrote:
> This patch creates APIs to save and restore the state of all
> peripheral clocks reset and enables.
>
> These APIs are invoked by Tegra210 clock driver during suspend and
> resume to save the peripheral clocks state before suspend and to
> restore them on resume.
>
> Signed-off-by: Sowjanya Komatineni <skomatineni@xxxxxxxxxx>
> ---
> drivers/clk/tegra/clk.c | 70 ++++++++++++++++++++++++++++++++++++++++++++++++-
> drivers/clk/tegra/clk.h | 3 +++
> 2 files changed, 72 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/clk/tegra/clk.c b/drivers/clk/tegra/clk.c
> index 26690663157a..bd3b46c5f941 100644
> --- a/drivers/clk/tegra/clk.c
> +++ b/drivers/clk/tegra/clk.c
> @@ -70,6 +70,7 @@ static struct clk **clks;
> static int clk_num;
> static struct clk_onecell_data clk_data;
>
> +static u32 *periph_ctx;
> static u32 cclkg_burst_policy_ctx[2];
> static u32 cclklp_burst_policy_ctx[2];
> static u32 sclk_burst_policy_ctx[2];
> @@ -279,6 +280,63 @@ void tegra_sclk_cpulp_burst_policy_restore_context(void)
> writel_relaxed(clk_arm_ctx, clk_base + CLK_MASK_ARM);
> }
>
> +void tegra_clk_periph_suspend(void __iomem *clk_base)
> +{
> + int i, idx;
Can be unsigned int. Same for below.
> +
> + idx = 0;
> + for (i = 0; i < periph_banks; i++, idx++)
> + periph_ctx[idx] =
> + readl_relaxed(clk_base + periph_regs[i].rst_reg);
> +
> + for (i = 0; i < periph_banks; i++, idx++)
> + periph_ctx[idx] =
> + readl_relaxed(clk_base + periph_regs[i].enb_reg);
> +}
> +
> +void tegra_clk_periph_force_on(u32 *clks_on, int count, void __iomem *clk_base)
count can also be unsigned int.
> +{
> + int i;
> +
> + WARN_ON(count != periph_banks);
> +
> + for (i = 0; i < count; i++)
> + writel_relaxed(clks_on[i], clk_base + periph_regs[i].enb_reg);
> +}
> +
> +void tegra_clk_periph_resume(void __iomem *clk_base)
> +{
> + int i, idx;
> +
> + idx = 0;
> + for (i = 0; i < periph_banks; i++, idx++)
> + writel_relaxed(periph_ctx[idx],
> + clk_base + periph_regs[i].rst_reg);
> +
> + /* ensure all resets have propagated */
> + fence_udelay(2, clk_base);
> + tegra_read_chipid();
> +
> + for (i = 0; i < periph_banks; i++, idx++)
> + writel_relaxed(periph_ctx[idx],
> + clk_base + periph_regs[i].enb_reg);
> +
> + /* ensure all enables have propagated */
> + fence_udelay(2, clk_base);
> + tegra_read_chipid();
> +}
> +
> +static int tegra_clk_suspend_ctx_init(int banks)
> +{
> + int err = 0;
> +
> + periph_ctx = kcalloc(2 * banks, sizeof(*periph_ctx), GFP_KERNEL);
> + if (!periph_ctx)
> + err = -ENOMEM;
> +
> + return err;
> +}
> +
> struct clk ** __init tegra_clk_init(void __iomem *regs, int num, int banks)
> {
> clk_base = regs;
> @@ -295,11 +353,21 @@ struct clk ** __init tegra_clk_init(void __iomem *regs, int num, int banks)
> periph_banks = banks;
>
> clks = kcalloc(num, sizeof(struct clk *), GFP_KERNEL);
> - if (!clks)
> + if (!clks) {
> kfree(periph_clk_enb_refcnt);
> + return NULL;
> + }
>
> clk_num = num;
>
> + if (IS_ENABLED(CONFIG_PM_SLEEP)) {
> + if (tegra_clk_suspend_ctx_init(banks)) {
> + kfree(periph_clk_enb_refcnt);
> + kfree(clks);
> + return NULL;
> + }
> + }
> +
> return clks;
> }
>
> diff --git a/drivers/clk/tegra/clk.h b/drivers/clk/tegra/clk.h
> index c8f8a23096e2..a354cacae5a6 100644
> --- a/drivers/clk/tegra/clk.h
> +++ b/drivers/clk/tegra/clk.h
> @@ -853,6 +853,9 @@ void tegra_cclkg_burst_policy_save_context(void);
> void tegra_cclkg_burst_policy_restore_context(void);
> void tegra_sclk_cclklp_burst_policy_save_context(void);
> void tegra_sclk_cpulp_burst_policy_restore_context(void);
> +void tegra_clk_periph_suspend(void __iomem *clk_base);
> +void tegra_clk_periph_resume(void __iomem *clk_base);
> +void tegra_clk_periph_force_on(u32 *clks_on, int count, void __iomem *clk_base);
>
> /* Combined read fence with delay */
> #define fence_udelay(delay, reg) \
Other than the nitpicks, looks good:
Acked-by: Thierry Reding <treding@xxxxxxxxxx>
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