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

[Dmitry Osipenko]

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>
>> ---
>>  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.
> 
> 		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]
>