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

Sowjanya Komatineni
2019-12-19T00:41:09Z

On 12/18/19 1:44 PM, Dmitry Osipenko wrote:
> 18.12.2019 11:35, Dmitry Osipenko пишет:
>> 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)

MUX Mask is used only here for PMC clock out and is same for all clk_out
mux so will use

#define PMC_CLK_OUT_MUX_MASK GENMASK(1, 0)

> I want to point out that may be a separated gate/mux shifts is a fine
> variant, you should try and see whether another variants produce more
> concise result.
>
> [snip]