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

[Sowjanya Komatineni <skomatineni@nvidia.com>]

On 12/19/19 5:39 PM, Dmitry Osipenko wrote:
> 20.12.2019 04:21, Sowjanya Komatineni пишет:
>> On 12/18/19 4:41 PM, Sowjanya Komatineni wrote:
>>> 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);
> Is this fencing applies only to clock changes or maybe it won't hurt to
> move it into tegra_pmc_writel()?
>
>>>>>>> +    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]
>> We can do mux_shift as gate_shift + 4 and that restricts this clk
>> register only for clk1/2/3 as well and there are no other clocks in pmc
>> anyway.
>>
>> How about using bit shift define for CLK1, CLK2, and CLK3?
>>
>> .mux_shift = PMC_CLK1_SRC_SEL_SHIFT,
>>
>> .gate_shift = PMC_CLK1_FORCE_EN_SHIFT,
>>
>>
> I think that just renaming ".gate_shift" -> ".force_en_shift" should be
> good enough.
You meant to assign bit position directly instead of defines like what I 
have now in v4 and use force_en_shift instead of gate_shift?