Re: [PATCH v4 06/19] soc: tegra: Add Tegra PMC clock registrations into PMC driver

Dmitry Osipenko
2019-12-18T08:30:29Z

17.12.2019 23:03, Sowjanya Komatineni пишет:
> Tegra PMC has clk_out_1, clk_out_2, and clk_out_3 clocks and currently
> these PMC clocks are registered by Tegra clock driver with each clock as
> separate mux and gate clocks using clk_register_mux and clk_register_gate
> by passing PMC base address and register offsets and PMC programming for
> these clocks happens through direct PMC access by the clock driver.
>
> With this, when PMC is in secure mode any direct PMC access from the
> non-secure world does not go through and these clocks will not be
> functional.
>
> This patch adds these PMC clocks registration to pmc driver with PMC as
> a clock provider and registers each clock as single clock.
>
> clk_ops callback implementations for these clocks uses tegra_pmc_readl and
> tegra_pmc_writel which supports PMC programming in both secure mode and
> non-secure mode.
>
> Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
> ---
> drivers/soc/tegra/pmc.c | 248 ++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 248 insertions(+)
>
> diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
> index ea0e11a09c12..6d65194a6e71 100644
> --- a/drivers/soc/tegra/pmc.c
> +++ b/drivers/soc/tegra/pmc.c
> @@ -13,6 +13,9 @@
>
> #include <linux/arm-smccc.h>
> #include <linux/clk.h>
> +#include <linux/clk-provider.h>
> +#include <linux/clkdev.h>
> +#include <linux/clk/clk-conf.h>
> #include <linux/clk/tegra.h>
> #include <linux/debugfs.h>
> #include <linux/delay.h>
> @@ -48,6 +51,7 @@
> #include <dt-bindings/pinctrl/pinctrl-tegra-io-pad.h>
> #include <dt-bindings/gpio/tegra186-gpio.h>
> #include <dt-bindings/gpio/tegra194-gpio.h>
> +#include <dt-bindings/soc/tegra-pmc.h>
>
> #define PMC_CNTRL 0x0
> #define PMC_CNTRL_INTR_POLARITY BIT(17) /* inverts INTR polarity */
> @@ -100,6 +104,7 @@
> #define PMC_WAKE2_STATUS 0x168
> #define PMC_SW_WAKE2_STATUS 0x16c
>
> +#define PMC_CLK_OUT_CNTRL 0x1a8
> #define PMC_SENSOR_CTRL 0x1b0
> #define PMC_SENSOR_CTRL_SCRATCH_WRITE BIT(2)
> #define PMC_SENSOR_CTRL_ENABLE_RST BIT(1)
> @@ -155,6 +160,64 @@
> #define TEGRA_SMC_PMC_READ 0xaa
> #define TEGRA_SMC_PMC_WRITE 0xbb
>
> +struct pmc_clk {
> + struct clk_hw hw;
> + unsigned long offs;
> + u32 mux_mask;
> + u32 mux_shift;
> + u32 gate_shift;
> +};
> +
> +#define to_pmc_clk(_hw) container_of(_hw, struct pmc_clk, hw)
> +
> +struct pmc_clk_init_data {
> + char *name;
> + const char *const *parents;
> + int num_parents;
> + int clk_id;
> + u8 mux_shift;
> + u8 gate_shift;
> +};
> +
> +static const char * const clk_out1_parents[] = { "osc", "osc_div2",
> + "osc_div4", "extern1",
> +};
> +
> +static const char * const clk_out2_parents[] = { "osc", "osc_div2",
> + "osc_div4", "extern2",
> +};
> +
> +static const char * const clk_out3_parents[] = { "osc", "osc_div2",
> + "osc_div4", "extern3",
> +};
> +
> +static const struct pmc_clk_init_data tegra_pmc_clks_data[] = {
> + {
> + .name = "clk_out_1",
> + .parents = clk_out1_parents,
> + .num_parents = ARRAY_SIZE(clk_out1_parents),
> + .clk_id = TEGRA_PMC_CLK_OUT_1,

> + .mux_shift = 6,
> + .gate_shift = 2,

I'd replace these with a single .shift, given that mux_shift =
gate_shift + 4 for all clocks.

> + },
> + {
> + .name = "clk_out_2",
> + .parents = clk_out2_parents,
> + .num_parents = ARRAY_SIZE(clk_out2_parents),
> + .clk_id = TEGRA_PMC_CLK_OUT_2,
> + .mux_shift = 14,
> + .gate_shift = 10,
> + },
> + {
> + .name = "clk_out_3",
> + .parents = clk_out3_parents,
> + .num_parents = ARRAY_SIZE(clk_out3_parents),
> + .clk_id = TEGRA_PMC_CLK_OUT_3,
> + .mux_shift = 22,
> + .gate_shift = 18,
> + },
> +};
> +
> struct tegra_powergate {
> struct generic_pm_domain genpd;
> struct tegra_pmc *pmc;
> @@ -254,6 +317,9 @@ struct tegra_pmc_soc {
> */
> const struct tegra_wake_event *wake_events;
> unsigned int num_wake_events;
> +
> + const struct pmc_clk_init_data *pmc_clks_data;
> + unsigned int num_pmc_clks;
> };
>
> static const char * const tegra186_reset_sources[] = {
> @@ -2163,6 +2229,173 @@ static int tegra_pmc_clk_notify_cb(struct notifier_block *nb,
> return NOTIFY_OK;
> }
>
> +static void pmc_clk_fence_udelay(u32 offset)
> +{
> + tegra_pmc_readl(pmc, offset);
> + /* pmc clk propagation delay 2 us */
> + udelay(2);
> +}
> +
> +static u8 pmc_clk_mux_get_parent(struct clk_hw *hw)
> +{
> + struct pmc_clk *clk = to_pmc_clk(hw);
> + u32 val;
> +
> + val = tegra_pmc_readl(pmc, clk->offs) >> clk->mux_shift;
> + val &= clk->mux_mask;
> +
> + return val;
> +}
> +
> +static int pmc_clk_mux_set_parent(struct clk_hw *hw, u8 index)
> +{
> + struct pmc_clk *clk = to_pmc_clk(hw);
> + u32 val;
> +
> + val = tegra_pmc_readl(pmc, clk->offs);
> + val &= ~(clk->mux_mask << clk->mux_shift);
> + val |= index << clk->mux_shift;
> + tegra_pmc_writel(pmc, val, clk->offs);
> + pmc_clk_fence_udelay(clk->offs);
> +
> + return 0;
> +}
> +
> +static int pmc_clk_is_enabled(struct clk_hw *hw)
> +{
> + struct pmc_clk *clk = to_pmc_clk(hw);
> +
> + return tegra_pmc_readl(pmc, clk->offs) & BIT(clk->gate_shift) ? 1 : 0;
> +}
> +
> +static void pmc_clk_set_state(unsigned long offs, u32 shift, int state)
> +{
> + u32 val;
> +
> + val = tegra_pmc_readl(pmc, offs);
> + val = state ? (val | BIT(shift)) : (val & ~BIT(shift));
> + tegra_pmc_writel(pmc, val, offs);
> + pmc_clk_fence_udelay(offs);
> +}
> +
> +static int pmc_clk_enable(struct clk_hw *hw)
> +{
> + struct pmc_clk *clk = to_pmc_clk(hw);
> +
> + pmc_clk_set_state(clk->offs, clk->gate_shift, 1);
> +
> + return 0;
> +}
> +
> +static void pmc_clk_disable(struct clk_hw *hw)
> +{
> + struct pmc_clk *clk = to_pmc_clk(hw);
> +
> + pmc_clk_set_state(clk->offs, clk->gate_shift, 0);
> +}
> +
> +static const struct clk_ops pmc_clk_ops = {
> + .get_parent = pmc_clk_mux_get_parent,
> + .set_parent = pmc_clk_mux_set_parent,
> + .determine_rate = __clk_mux_determine_rate,
> + .is_enabled = pmc_clk_is_enabled,
> + .enable = pmc_clk_enable,
> + .disable = pmc_clk_disable,
> +};
> +
> +static struct clk *
> +tegra_pmc_clk_out_register(const struct pmc_clk_init_data *data,
> + unsigned long offset)
> +{
> + struct clk_init_data init;
> + struct pmc_clk *pmc_clk;
> +
> + pmc_clk = kzalloc(sizeof(*pmc_clk), GFP_KERNEL);
> + if (!pmc_clk)
> + return ERR_PTR(-ENOMEM);
> +
> + init.name = data->name;
> + init.ops = &pmc_clk_ops;
> + init.parent_names = data->parents;
> + init.num_parents = data->num_parents;
> + init.flags = CLK_SET_RATE_NO_REPARENT | CLK_SET_RATE_PARENT |
> + CLK_SET_PARENT_GATE;
> +
> + pmc_clk->hw.init = &init;
> + pmc_clk->offs = offset;
> + pmc_clk->mux_mask = 3;

If mux_mask is a constant value, perhaps will be better to replace the
variable with a literal?

#define PMC_CLK_OUT_MUX_MASK GENMASK(1, 0)

> + pmc_clk->mux_shift = data->mux_shift;
> + pmc_clk->gate_shift = data->gate_shift;
> +
> + return clk_register(NULL, &pmc_clk->hw);
> +}
> +
> +static void tegra_pmc_clock_register(struct tegra_pmc *pmc,
> + struct device_node *np)
> +{
> + struct clk *clk;
> + struct clk_onecell_data *clk_data;
> + unsigned int num_clks;
> + int i, err = -ENOMEM;
> +
> + num_clks = pmc->soc->num_pmc_clks;
> +
> + if (!num_clks)
> + return;
> +
> + clk_data = kmalloc(sizeof(*clk_data), GFP_KERNEL);
> + if (!clk_data)
> + goto err_clk;

What about devm_kmalloc, devm_kcalloc?

> + clk_data->clks = kcalloc(TEGRA_PMC_CLK_MAX, sizeof(*clk_data->clks),
> + GFP_KERNEL);
> + if (!clk_data->clks)
> + goto free_clkdata;
> +
> + clk_data->clk_num = TEGRA_PMC_CLK_MAX;
> +
> + for (i = 0; i < TEGRA_PMC_CLK_MAX; i++)
> + clk_data->clks[i] = ERR_PTR(-ENOENT);
> +
> + for (i = 0; i < pmc->soc->num_pmc_clks; i++) {
> + const struct pmc_clk_init_data *data;
> +
> + data = pmc->soc->pmc_clks_data + i;
> +
> + clk = tegra_pmc_clk_out_register(data, PMC_CLK_OUT_CNTRL);> + if (IS_ERR(clk)) {
> + dev_err(pmc->dev,
> + "unable to register %s\n", data->name);
> + err = PTR_ERR(clk);
Error codes in a message could be useful.

err = PTR_ERR_OR_ZERO(clk);
if (err)
dev_err(pmc->dev, "unable to register %s: %d\n",
data->name, err);

> + goto free_clks;
> + }

- clk_data->clks[data->clk_id] = clk;

> + err = clk_register_clkdev(clk, data->name, NULL);
> + if (err) {
> + dev_err(pmc->dev,
> + "unable to register %s clock lookup\n",
> + data->name);

dev_err(pmc->dev,
"unable to register %s clock lookup: %d\n",
data->name, err);

> + goto free_clks;
> + }

I'd move the assignment here for a bit more consistency.

+ clk_data->clks[data->clk_id] = clk;

> + }
> +
> + err = of_clk_add_provider(np, of_clk_src_onecell_get, clk_data);
> + if (err) {
> + dev_err(pmc->dev, "failed to add pmc clk provider\n");
> + goto free_clks;
> + }

[snip]