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

Dmitry Osipenko
2019-12-18T08:35:50Z

18.12.2019 11:30, Dmitry Osipenko пишет:
> 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)

Maybe even:

#define PMC_CLK_OUT_MUX_MASK(c) GENMASK(c->shift + 1, c->shift)

>> + 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]
>