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

Dmitry Osipenko
2019-12-18T16:48:13Z

18.12.2019 18:46, Sowjanya Komatineni пишет:
>
> 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.

What about dev_WARN()?