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

Sowjanya Komatineni
2019-12-18T15:46:31Z

On 12/18/19 12:35 AM, Dmitry Osipenko wrote:
> 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.

Added error code at end of clock register along with WARN message to
have it common to show warning with error code for all errors including
kmalloc and kcalloc.

>>
>> 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]
>>