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

[Dmitry Osipenko]

18.12.2019 18:50, Sowjanya Komatineni ÐÐÑÐÑ:
> 
> On 12/18/19 7:46 AM, Sowjanya Komatineni wrote:
>>
>> On 12/18/19 12:35 AM, Dmitry Osipenko wrote:
>>> 18.12.2019 11:30, Dmitry Osipenko ÐÐÑÐÑ:
>>>> 17.12.2019 23:03, Sowjanya Komatineni ÐÐÑÐÑ:
>>>>> 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@xxxxxxxxxx>
>>>>> ---
>>>>> Â drivers/soc/tegra/pmc.c | 248
>>>>> ++++++++++++++++++++++++++++++++++++++++++++++++
>>>>> Â 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 @@
>>>>> Â Â #include <linux/arm-smccc.h>
>>>>> Â #include <linux/clk.h>
>>>>> +#include <linux/clk-provider.h>
>>>>> +#include <linux/clkdev.h>
>>>>> +#include <linux/clk/clk-conf.h>
>>>>> Â #include <linux/clk/tegra.h>
>>>>> Â #include <linux/debugfs.h>
>>>>> Â #include <linux/delay.h>
>>>>> @@ -48,6 +51,7 @@
>>>>> Â #include <dt-bindings/pinctrl/pinctrl-tegra-io-pad.h>
>>>>> Â #include <dt-bindings/gpio/tegra186-gpio.h>
>>>>> Â #include <dt-bindings/gpio/tegra194-gpio.h>
>>>>> +#include <dt-bindings/soc/tegra-pmc.h>
>>>>> Â Â #define PMC_CNTRLÂÂÂÂÂÂÂÂÂÂÂ 0x0
>>>>>  #define PMC_CNTRL_INTR_POLARITY BIT(17) /* inverts INTR
>>>>> polarity */
>>>>> @@ -100,6 +104,7 @@
>>>>> Â #define PMC_WAKE2_STATUSÂÂÂÂÂÂÂ 0x168
>>>>> Â #define PMC_SW_WAKE2_STATUSÂÂÂÂÂÂÂ 0x16c
>>>>> Â +#define PMC_CLK_OUT_CNTRLÂÂÂÂÂÂÂ 0x1a8
>>>>> Â #define PMC_SENSOR_CTRLÂÂÂÂÂÂÂÂÂÂÂ 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
>>>>> Â +struct pmc_clk {
>>>>> +ÂÂÂ struct clk_hwÂÂÂ hw;
>>>>> +ÂÂÂ unsigned longÂÂÂ offs;
>>>>> +ÂÂÂ u32ÂÂÂÂÂÂÂ mux_mask;
>>>>> +ÂÂÂ u32ÂÂÂÂÂÂÂ mux_shift;
>>>>> +ÂÂÂ u32ÂÂÂÂÂÂÂ gate_shift;
>>>>> +};
>>>>> +
>>>>> +#define to_pmc_clk(_hw) container_of(_hw, struct pmc_clk, hw)
>>>>> +
>>>>> +struct pmc_clk_init_data {
>>>>> +ÂÂÂ char *name;
>>>>> +ÂÂÂ const char *const *parents;
>>>>> +ÂÂÂ int num_parents;
>>>>> +ÂÂÂ int clk_id;
>>>>> +ÂÂÂ u8 mux_shift;
>>>>> +ÂÂÂ u8 gate_shift;
>>>>> +};
>>>>> +
>>>>> +static const char * const clk_out1_parents[] = { "osc", "osc_div2",
>>>>> +ÂÂÂ "osc_div4", "extern1",
>>>>> +};
>>>>> +
>>>>> +static const char * const clk_out2_parents[] = { "osc", "osc_div2",
>>>>> +ÂÂÂ "osc_div4", "extern2",
>>>>> +};
>>>>> +
>>>>> +static const char * const clk_out3_parents[] = { "osc", "osc_div2",
>>>>> +ÂÂÂ "osc_div4", "extern3",
>>>>> +};
>>>>> +
>>>>> +static const struct pmc_clk_init_data tegra_pmc_clks_data[] = {
>>>>> +ÂÂÂ {
>>>>> +ÂÂÂÂÂÂÂ .name = "clk_out_1",
>>>>> +ÂÂÂÂÂÂÂ .parents = clk_out1_parents,
>>>>> +ÂÂÂÂÂÂÂ .num_parents = ARRAY_SIZE(clk_out1_parents),
>>>>> +ÂÂÂÂÂÂÂ .clk_id = TEGRA_PMC_CLK_OUT_1,
>>>>> +ÂÂÂÂÂÂÂ .mux_shift = 6,
>>>>> +ÂÂÂÂÂÂÂ .gate_shift = 2,
>>>> I'd replace these with a single .shift, given that mux_shift =
>>>> gate_shift + 4 for all clocks.
>>>>
>>>>> +ÂÂÂ },
>>>>> +ÂÂÂ {
>>>>> +ÂÂÂÂÂÂÂ .name = "clk_out_2",
>>>>> +ÂÂÂÂÂÂÂ .parents = clk_out2_parents,
>>>>> +ÂÂÂÂÂÂÂ .num_parents = ARRAY_SIZE(clk_out2_parents),
>>>>> +ÂÂÂÂÂÂÂ .clk_id = TEGRA_PMC_CLK_OUT_2,
>>>>> +ÂÂÂÂÂÂÂ .mux_shift = 14,
>>>>> +ÂÂÂÂÂÂÂ .gate_shift = 10,
>>>>> +ÂÂÂ },
>>>>> +ÂÂÂ {
>>>>> +ÂÂÂÂÂÂÂ .name = "clk_out_3",
>>>>> +ÂÂÂÂÂÂÂ .parents = clk_out3_parents,
>>>>> +ÂÂÂÂÂÂÂ .num_parents = ARRAY_SIZE(clk_out3_parents),
>>>>> +ÂÂÂÂÂÂÂ .clk_id = TEGRA_PMC_CLK_OUT_3,
>>>>> +ÂÂÂÂÂÂÂ .mux_shift = 22,
>>>>> +ÂÂÂÂÂÂÂ .gate_shift = 18,
>>>>> +ÂÂÂ },
>>>>> +};
>>>>> +
>>>>> Â struct tegra_powergate {
>>>>> ÂÂÂÂÂ struct generic_pm_domain genpd;
>>>>> ÂÂÂÂÂ struct tegra_pmc *pmc;
>>>>> @@ -254,6 +317,9 @@ struct tegra_pmc_soc {
>>>>> ÂÂÂÂÂÂ */
>>>>> ÂÂÂÂÂ const struct tegra_wake_event *wake_events;
>>>>> ÂÂÂÂÂ unsigned int num_wake_events;
>>>>> +
>>>>> +ÂÂÂ const struct pmc_clk_init_data *pmc_clks_data;
>>>>> +ÂÂÂ unsigned int num_pmc_clks;
>>>>> Â };
>>>>> Â Â static const char * const tegra186_reset_sources[] = {
>>>>> @@ -2163,6 +2229,173 @@ static int tegra_pmc_clk_notify_cb(struct
>>>>> notifier_block *nb,
>>>>> ÂÂÂÂÂ return NOTIFY_OK;
>>>>> Â }
>>>>> Â +static void pmc_clk_fence_udelay(u32 offset)
>>>>> +{
>>>>> +ÂÂÂ tegra_pmc_readl(pmc, offset);
>>>>> +ÂÂÂ /* pmc clk propagation delay 2 us */
>>>>> +ÂÂÂ udelay(2);
>>>>> +}
>>>>> +
>>>>> +static u8 pmc_clk_mux_get_parent(struct clk_hw *hw)
>>>>> +{
>>>>> +ÂÂÂ struct pmc_clk *clk = to_pmc_clk(hw);
>>>>> +ÂÂÂ u32 val;
>>>>> +
>>>>> +ÂÂÂ val = tegra_pmc_readl(pmc, clk->offs) >> clk->mux_shift;
>>>>> +ÂÂÂ val &= clk->mux_mask;
>>>>> +
>>>>> +ÂÂÂ return val;
>>>>> +}
>>>>> +
>>>>> +static int pmc_clk_mux_set_parent(struct clk_hw *hw, u8 index)
>>>>> +{
>>>>> +ÂÂÂ struct pmc_clk *clk = to_pmc_clk(hw);
>>>>> +ÂÂÂ u32 val;
>>>>> +
>>>>> +ÂÂÂ val = tegra_pmc_readl(pmc, clk->offs);
>>>>> +ÂÂÂ val &= ~(clk->mux_mask << clk->mux_shift);
>>>>> +ÂÂÂ val |= index << clk->mux_shift;
>>>>> +ÂÂÂ tegra_pmc_writel(pmc, val, clk->offs);
>>>>> +ÂÂÂ pmc_clk_fence_udelay(clk->offs);
>>>>> +
>>>>> +ÂÂÂ return 0;
>>>>> +}
>>>>> +
>>>>> +static int pmc_clk_is_enabled(struct clk_hw *hw)
>>>>> +{
>>>>> +ÂÂÂ struct pmc_clk *clk = to_pmc_clk(hw);
>>>>> +
>>>>> +ÂÂÂ 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)
>>>>> +{
>>>>> +ÂÂÂ u32 val;
>>>>> +
>>>>> +ÂÂÂ val = tegra_pmc_readl(pmc, offs);
>>>>> +ÂÂÂ val = state ? (val | BIT(shift)) : (val & ~BIT(shift));
>>>>> +ÂÂÂ tegra_pmc_writel(pmc, val, offs);
>>>>> +ÂÂÂ pmc_clk_fence_udelay(offs);
>>>>> +}
>>>>> +
>>>>> +static int pmc_clk_enable(struct clk_hw *hw)
>>>>> +{
>>>>> +ÂÂÂ struct pmc_clk *clk = to_pmc_clk(hw);
>>>>> +
>>>>> +ÂÂÂ pmc_clk_set_state(clk->offs, clk->gate_shift, 1);
>>>>> +
>>>>> +ÂÂÂ return 0;
>>>>> +}
>>>>> +
>>>>> +static void pmc_clk_disable(struct clk_hw *hw)
>>>>> +{
>>>>> +ÂÂÂ struct pmc_clk *clk = to_pmc_clk(hw);
>>>>> +
>>>>> +ÂÂÂ pmc_clk_set_state(clk->offs, clk->gate_shift, 0);
>>>>> +}
>>>>> +
>>>>> +static const struct clk_ops pmc_clk_ops = {
>>>>> +ÂÂÂ .get_parent = pmc_clk_mux_get_parent,
>>>>> +ÂÂÂ .set_parent = pmc_clk_mux_set_parent,
>>>>> +ÂÂÂ .determine_rate = __clk_mux_determine_rate,
>>>>> +ÂÂÂ .is_enabled = pmc_clk_is_enabled,
>>>>> +ÂÂÂ .enable = pmc_clk_enable,
>>>>> +ÂÂÂ .disable = pmc_clk_disable,
>>>>> +};
>>>>> +
>>>>> +static struct clk *
>>>>> +tegra_pmc_clk_out_register(const struct pmc_clk_init_data *data,
>>>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂ unsigned long offset)
>>>>> +{
>>>>> +ÂÂÂ struct clk_init_data init;
>>>>> +ÂÂÂ struct pmc_clk *pmc_clk;
>>>>> +
>>>>> +ÂÂÂ pmc_clk = kzalloc(sizeof(*pmc_clk), GFP_KERNEL);
>>>>> +ÂÂÂ if (!pmc_clk)
>>>>> +ÂÂÂÂÂÂÂ return ERR_PTR(-ENOMEM);
>>>>> +
>>>>> +ÂÂÂ init.name = data->name;
>>>>> +ÂÂÂ init.ops = &pmc_clk_ops;
>>>>> +ÂÂÂ init.parent_names = data->parents;
>>>>> +ÂÂÂ init.num_parents = data->num_parents;
>>>>> +ÂÂÂ init.flags = CLK_SET_RATE_NO_REPARENT | CLK_SET_RATE_PARENT |
>>>>> +ÂÂÂÂÂÂÂÂÂÂÂÂ CLK_SET_PARENT_GATE;
>>>>> +
>>>>> +ÂÂÂ pmc_clk->hw.init = &init;
>>>>> +ÂÂÂ pmc_clk->offs = offset;
>>>>> +ÂÂÂ 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_MASKÂÂÂ GENMASK(1, 0)
>>> Maybe even:
>>>
>>> #define PMC_CLK_OUT_MUX_MASK(c)ÂÂÂ GENMASK(c->shift + 1, c->shift)
>>>
>>>>> +ÂÂÂ pmc_clk->mux_shift = data->mux_shift;
>>>>> +ÂÂÂ pmc_clk->gate_shift = data->gate_shift;
>>>>> +
>>>>> +ÂÂÂ return clk_register(NULL, &pmc_clk->hw);
>>>>> +}
>>>>> +
>>>>> +static void tegra_pmc_clock_register(struct tegra_pmc *pmc,
>>>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ struct device_node *np)
>>>>> +{
>>>>> +ÂÂÂ struct clk *clk;
>>>>> +ÂÂÂ struct clk_onecell_data *clk_data;
>>>>> +ÂÂÂ unsigned int num_clks;
>>>>> +ÂÂÂ int i, err = -ENOMEM;
>>>>> +
>>>>> +ÂÂÂ num_clks = pmc->soc->num_pmc_clks;
>>>>> +
>>>>> +ÂÂÂ if (!num_clks)
>>>>> +ÂÂÂÂÂÂÂ return;
>>>>> +
>>>>> +ÂÂÂ clk_data = kmalloc(sizeof(*clk_data), GFP_KERNEL);
>>>>> +ÂÂÂ if (!clk_data)
>>>>> +ÂÂÂÂÂÂÂ goto err_clk;
>>>> What about devm_kmalloc, devm_kcalloc?
>>>>
>>>>> +ÂÂÂ clk_data->clks = kcalloc(TEGRA_PMC_CLK_MAX,
>>>>> sizeof(*clk_data->clks),
>>>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ GFP_KERNEL);
>>>>> +ÂÂÂ if (!clk_data->clks)
>>>>> +ÂÂÂÂÂÂÂ goto free_clkdata;
>>>>> +
>>>>> +ÂÂÂ clk_data->clk_num = TEGRA_PMC_CLK_MAX;
>>>>> +
>>>>> +ÂÂÂ for (i = 0; i < TEGRA_PMC_CLK_MAX; i++)
>>>>> +ÂÂÂÂÂÂÂ clk_data->clks[i] = ERR_PTR(-ENOENT);
>>>>> +
>>>>> +ÂÂÂ for (i = 0; i < pmc->soc->num_pmc_clks; i++) {
>>>>> +ÂÂÂÂÂÂÂ const struct pmc_clk_init_data *data;
>>>>> +
>>>>> +ÂÂÂÂÂÂÂ data = pmc->soc->pmc_clks_data + i;
>>>>> +
>>>>> +ÂÂÂÂÂÂÂ clk = tegra_pmc_clk_out_register(data,
>>>>> PMC_CLK_OUT_CNTRL);> +ÂÂÂÂÂÂÂ if (IS_ERR(clk)) {
>>>>> +ÂÂÂÂÂÂÂÂÂÂÂ dev_err(pmc->dev,
>>>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ "unable to register %s\n", data->name);
>>>>> +ÂÂÂÂÂÂÂÂÂÂÂ 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.
>>
> Sure, With devm_kmalloc and devm_kcalloc, will move error code along
> with message and do return right at point of errors.

There is no need to warn about memory allocations because there will be
warning anyway, unless __GFP_NOWARN is used.