Re: [PATCH v2 02/11] soc: tegra: Add Tegra PMC clock registrations into PMC driver

From: Dmitry Osipenko
Date: Thu Nov 28 2019 - 08:27:03 EST


28.11.2019 01:57, Sowjanya Komatineni ÐÐÑÐÑ:
>
> On 11/27/19 7:14 AM, Dmitry Osipenko wrote:
>> 27.11.2019 07:59, Sowjanya Komatineni ÐÐÑÐÑ:
>>> Tegra210 and prior Tegra PMC has clk_out_1, clk_out_2, clk_out_3 with
>>> mux and gate for each of these clocks.
>>>
>>> Currently these PMC clocks are registered by Tegra clock driver 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 clocks registration with PMC as a clock provider
>>> for these clocks. clk_ops callback implementations for these clocks
>>> uses tegra_pmc_readl and tegra_pmc_writel which supports PMC programming
>>> in secure mode and non-secure mode.
>>>
>>> Signed-off-by: Sowjanya Komatineni <skomatineni@xxxxxxxxxx>
>>> ---
>>> Â drivers/soc/tegra/pmc.c | 330
>>> ++++++++++++++++++++++++++++++++++++++++++++++++
>>> Â 1 file changed, 330 insertions(+)
>>>
>>> diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
>>> index ea0e11a09c12..a353f6d0a832 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 +160,91 @@
>>>  #define TEGRA_SMC_PMC_READ 0xaa
>>>  #define TEGRA_SMC_PMC_WRITE 0xbb
>>> Â +struct pmc_clk_mux {
>>> +ÂÂÂ struct clk_hwÂÂÂ hw;
>>> +ÂÂÂ unsigned longÂÂÂ offs;
>>> +ÂÂÂ u32ÂÂÂÂÂÂÂ mask;
>>> +ÂÂÂ u32ÂÂÂÂÂÂÂ shift;
>>> +};
>>> +
>>> +#define to_pmc_clk_mux(_hw) container_of(_hw, struct pmc_clk_mux, hw)
>>> +
>>> +struct pmc_clk_gate {
>>> +ÂÂÂ struct clk_hwÂÂÂ hw;
>>> +ÂÂÂ unsigned longÂÂÂ offs;
>>> +ÂÂÂ u32ÂÂÂÂÂÂÂ shift;
>>> +};
>>> +
>>> +#define to_pmc_clk_gate(_hw) container_of(_hw, struct pmc_clk_gate, hw)
>>> +
>>> +struct pmc_clk_init_data {
>>> +ÂÂÂ char *mux_name;
>>> +ÂÂÂ char *gate_name;
>>> +ÂÂÂ const char **parents;
>>> +ÂÂÂ int num_parents;
>>> +ÂÂÂ int mux_id;
>>> +ÂÂÂ int gate_id;
>>> +ÂÂÂ char *dev_name;
>>> +ÂÂÂ u8 mux_shift;
>>> +ÂÂÂ u8 gate_shift;
>>> +ÂÂÂ u8 init_parent_index;
>>> +ÂÂÂ int init_state;
>>> +};
>>> +
>>> +static const char *clk_out1_parents[] = { "clk_m", "clk_m_div2",
>>> +ÂÂÂ "clk_m_div4", "extern1",
>>> +};
>>> +
>>> +static const char *clk_out2_parents[] = { "clk_m", "clk_m_div2",
>>> +ÂÂÂ "clk_m_div4", "extern2",
>>> +};
>>> +
>>> +static const char *clk_out3_parents[] = { "clk_m", "clk_m_div2",
>>> +ÂÂÂ "clk_m_div4", "extern3",
>>> +};
>>> +
>>> +static struct pmc_clk_init_data tegra_pmc_clks_data[] = {
>>> +ÂÂÂ {
>>> +ÂÂÂÂÂÂÂ .mux_name = "clk_out_1_mux",
>>> +ÂÂÂÂÂÂÂ .gate_name = "clk_out_1",
>>> +ÂÂÂÂÂÂÂ .parents = clk_out1_parents,
>>> +ÂÂÂÂÂÂÂ .num_parents = ARRAY_SIZE(clk_out1_parents),
>>> +ÂÂÂÂÂÂÂ .mux_id = TEGRA_PMC_CLK_OUT_1_MUX,
>>> +ÂÂÂÂÂÂÂ .gate_id = TEGRA_PMC_CLK_OUT_1,
>>> +ÂÂÂÂÂÂÂ .dev_name = "extern1",
>>> +ÂÂÂÂÂÂÂ .mux_shift = 6,
>>> +ÂÂÂÂÂÂÂ .gate_shift = 2,
>>> +ÂÂÂÂÂÂÂ .init_parent_index = 3,
>>> +ÂÂÂÂÂÂÂ .init_state = 1,
>>> +ÂÂÂ },
>>> +ÂÂÂ {
>>> +ÂÂÂÂÂÂÂ .mux_name = "clk_out_2_mux",
>>> +ÂÂÂÂÂÂÂ .gate_name = "clk_out_2",
>>> +ÂÂÂÂÂÂÂ .parents = clk_out2_parents,
>>> +ÂÂÂÂÂÂÂ .num_parents = ARRAY_SIZE(clk_out2_parents),
>>> +ÂÂÂÂÂÂÂ .mux_id = TEGRA_PMC_CLK_OUT_2_MUX,
>>> +ÂÂÂÂÂÂÂ .gate_id = TEGRA_PMC_CLK_OUT_2,
>>> +ÂÂÂÂÂÂÂ .dev_name = "extern2",
>>> +ÂÂÂÂÂÂÂ .mux_shift = 14,
>>> +ÂÂÂÂÂÂÂ .gate_shift = 10,
>>> +ÂÂÂÂÂÂÂ .init_parent_index = 0,
>>> +ÂÂÂÂÂÂÂ .init_state = 0,
>>> +ÂÂÂ },
>>> +ÂÂÂ {
>>> +ÂÂÂÂÂÂÂ .mux_name = "clk_out_3_mux",
>>> +ÂÂÂÂÂÂÂ .gate_name = "clk_out_3",
>>> +ÂÂÂÂÂÂÂ .parents = clk_out3_parents,
>>> +ÂÂÂÂÂÂÂ .num_parents = ARRAY_SIZE(clk_out3_parents),
>>> +ÂÂÂÂÂÂÂ .mux_id = TEGRA_PMC_CLK_OUT_3_MUX,
>>> +ÂÂÂÂÂÂÂ .gate_id = TEGRA_PMC_CLK_OUT_3,
>>> +ÂÂÂÂÂÂÂ .dev_name = "extern3",
>>> +ÂÂÂÂÂÂÂ .mux_shift = 22,
>>> +ÂÂÂÂÂÂÂ .gate_shift = 18,
>>> +ÂÂÂÂÂÂÂ .init_parent_index = 0,
>>> +ÂÂÂÂÂÂÂ .init_state = 0,
>>> +ÂÂÂ },
>>> +};
>>> +
>>> Â struct tegra_powergate {
>>> ÂÂÂÂÂ struct generic_pm_domain genpd;
>>> ÂÂÂÂÂ struct tegra_pmc *pmc;
>>> @@ -254,6 +344,9 @@ struct tegra_pmc_soc {
>>> ÂÂÂÂÂÂ */
>>> ÂÂÂÂÂ const struct tegra_wake_event *wake_events;
>>> ÂÂÂÂÂ unsigned int num_wake_events;
>>> +
>>> +ÂÂÂ 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 +2256,228 @@ 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_mux *mux = to_pmc_clk_mux(hw);
>>> +ÂÂÂ int num_parents = clk_hw_get_num_parents(hw);
>>> +ÂÂÂ u32 val;
>>> +
>>> +ÂÂÂ val = tegra_pmc_readl(pmc, mux->offs) >> mux->shift;
>>> +ÂÂÂ val &= mux->mask;
>>> +
>>> +ÂÂÂ if (val >= num_parents)
>>> +ÂÂÂÂÂÂÂ return -EINVAL;
>>> +
>>> +ÂÂÂ return val;
>>> +}
>>> +
>>> +static int pmc_clk_mux_set_parent(struct clk_hw *hw, u8 index)
>>> +{
>>> +ÂÂÂ struct pmc_clk_mux *mux = to_pmc_clk_mux(hw);
>>> +ÂÂÂ u32 val;
>>> +
>>> +ÂÂÂ val = tegra_pmc_readl(pmc, mux->offs);
>>> +ÂÂÂ val &= ~(mux->mask << mux->shift);
>>> +ÂÂÂ val |= index << mux->shift;
>>> +ÂÂÂ tegra_pmc_writel(pmc, val, mux->offs);
>>> +ÂÂÂ pmc_clk_fence_udelay(mux->offs);
>>> +
>>> +ÂÂÂ return 0;
>>> +}
>>> +
>>> +static const struct clk_ops pmc_clk_mux_ops = {
>>> +ÂÂÂ .get_parent = pmc_clk_mux_get_parent,
>>> +ÂÂÂ .set_parent = pmc_clk_mux_set_parent,
>>> +ÂÂÂ .determine_rate = __clk_mux_determine_rate,
>>> +};
>>> +
>>> +static struct clk *
>>> +tegra_pmc_clk_mux_register(const char *name, const char * const
>>> *parent_names,
>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂ int num_parents, unsigned long flags,
>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂ unsigned long offset, u32 shift, u32 mask)
>>> +{
>>> +ÂÂÂ struct clk_init_data init;
>>> +ÂÂÂ struct pmc_clk_mux *mux;
>>> +
>>> +ÂÂÂ mux = kzalloc(sizeof(*mux), GFP_KERNEL);
>>> +ÂÂÂ if (!mux)
>>> +ÂÂÂÂÂÂÂ return ERR_PTR(-ENOMEM);
>>> +
>>> +ÂÂÂ init.name = name;
>>> +ÂÂÂ init.ops = &pmc_clk_mux_ops;
>>> +ÂÂÂ init.parent_names = parent_names;
>>> +ÂÂÂ init.num_parents = num_parents;
>>> +ÂÂÂ init.flags = flags;
>>> +
>>> +ÂÂÂ mux->hw.init = &init;
>>> +ÂÂÂ mux->offs = offset;
>>> +ÂÂÂ mux->mask = mask;
>>> +ÂÂÂ mux->shift = shift;
>>> +
>>> +ÂÂÂ return clk_register(NULL, &mux->hw);
>>> +}
>>> +
>>> +static int pmc_clk_is_enabled(struct clk_hw *hw)
>>> +{
>>> +ÂÂÂ struct pmc_clk_gate *gate = to_pmc_clk_gate(hw);
>>> +
>>> +ÂÂÂ return tegra_pmc_readl(pmc, gate->offs) & BIT(gate->shift) ? 1 : 0;
>>> +}
>>> +
>>> +static void pmc_clk_set_state(struct clk_hw *hw, int state)
>>> +{
>>> +ÂÂÂ struct pmc_clk_gate *gate = to_pmc_clk_gate(hw);
>>> +ÂÂÂ u32 val;
>>> +
>>> +ÂÂÂ val = tegra_pmc_readl(pmc, gate->offs);
>>> +ÂÂÂ val = state ? (val | BIT(gate->shift)) : (val & ~BIT(gate->shift));
>>> +ÂÂÂ tegra_pmc_writel(pmc, val, gate->offs);
>>> +ÂÂÂ pmc_clk_fence_udelay(gate->offs);
>>> +}
>>> +
>>> +static int pmc_clk_enable(struct clk_hw *hw)
>>> +{
>>> +ÂÂÂ pmc_clk_set_state(hw, 1);
>>> +
>>> +ÂÂÂ return 0;
>>> +}
>>> +
>>> +static void pmc_clk_disable(struct clk_hw *hw)
>>> +{
>>> +ÂÂÂ pmc_clk_set_state(hw, 0);
>>> +}
>>> +
>>> +static const struct clk_ops pmc_clk_gate_ops = {
>>> +ÂÂÂ .is_enabled = pmc_clk_is_enabled,
>>> +ÂÂÂ .enable = pmc_clk_enable,
>>> +ÂÂÂ .disable = pmc_clk_disable,
>>> +};
>>> +
>>> +static struct clk *
>>> +tegra_pmc_clk_gate_register(const char *name, const char *parent_name,
>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ unsigned long flags, unsigned long offset,
>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ u32 shift)
>>> +{
>>> +ÂÂÂ struct clk_init_data init;
>>> +ÂÂÂ struct pmc_clk_gate *gate;
>>> +
>>> +ÂÂÂ gate = kzalloc(sizeof(*gate), GFP_KERNEL);
>>> +ÂÂÂ if (!gate)
>>> +ÂÂÂÂÂÂÂ return ERR_PTR(-ENOMEM);
>>> +
>>> +ÂÂÂ init.name = name;
>>> +ÂÂÂ init.ops = &pmc_clk_gate_ops;
>>> +ÂÂÂ init.parent_names = &parent_name;
>>> +ÂÂÂ init.num_parents = 1;
>>> +ÂÂÂ init.flags = flags;
>>> +
>>> +ÂÂÂ gate->hw.init = &init;
>>> +ÂÂÂ gate->offs = offset;
>>> +ÂÂÂ gate->shift = shift;
>>> +
>>> +ÂÂÂ return clk_register(NULL, &gate->hw);
>>> +}
>>> +
>>> +static void tegra_pmc_clock_register(struct tegra_pmc *pmc,
>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ struct device_node *np)
>>> +{
>>> +ÂÂÂ struct clk *clkmux, *clk, *parent;
>>> +ÂÂÂ struct clk_onecell_data *clk_data;
>>> +ÂÂÂ unsigned int num_clks;
>>> +ÂÂÂ int i, ret;
>>> +
>>> +ÂÂÂ /* each pmc clock output has a mux and a gate */
>>> +ÂÂÂ num_clks = pmc->soc->num_pmc_clks * 2;
>>> +
>>> +ÂÂÂ if (!num_clks)
>>> +ÂÂÂÂÂÂÂ return;
>>> +
>>> +ÂÂÂ clk_data = kmalloc(sizeof(*clk_data), GFP_KERNEL);
>>> +ÂÂÂ if (!clk_data)
>>> +ÂÂÂÂÂÂÂ return;
>>> +
>>> +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 = num_clks;
>>> +
>>> +ÂÂÂ for (i = 0; i < pmc->soc->num_pmc_clks; i++) {
>>> +ÂÂÂÂÂÂÂ struct pmc_clk_init_data *data;
>>> +
>>> +ÂÂÂÂÂÂÂ data = pmc->soc->pmc_clks_data + i;
>>> +
>>> +ÂÂÂÂÂÂÂ clkmux = tegra_pmc_clk_mux_register(data->mux_name,
>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ data->parents,
>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ data->num_parents,
>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ CLK_SET_RATE_NO_REPARENT |
>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ CLK_SET_RATE_PARENT,
>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ PMC_CLK_OUT_CNTRL,
>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ data->mux_shift, 3);
>>> +ÂÂÂÂÂÂÂ if (IS_ERR(clkmux))
>>> +ÂÂÂÂÂÂÂÂÂÂÂ goto free_clks;
>>> +
>>> +ÂÂÂÂÂÂÂ clk_data->clks[data->mux_id] = clkmux;
>>> +
>>> +ÂÂÂÂÂÂÂ clk = tegra_pmc_clk_gate_register(data->gate_name,
>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ data->mux_name,
>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ CLK_SET_RATE_PARENT,
>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ PMC_CLK_OUT_CNTRL,
>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ data->gate_shift);
>>> +ÂÂÂÂÂÂÂ if (IS_ERR(clk))
>>> +ÂÂÂÂÂÂÂÂÂÂÂ goto free_clks;
>>> +
>>> +ÂÂÂÂÂÂÂ clk_data->clks[data->gate_id] = clk;
>>> +
>>> +ÂÂÂÂÂÂÂ ret = clk_set_parent(clk, clkmux);
>>> +ÂÂÂÂÂÂÂ if (ret < 0) {
>>> +ÂÂÂÂÂÂÂÂÂÂÂ pr_err("failed to set parent of %s to %s\n",
>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ __func__, __clk_get_name(clk),
>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ __clk_get_name(clkmux));
>>> +ÂÂÂÂÂÂÂ }
>>> +
>>> +ÂÂÂÂÂÂÂ clk_register_clkdev(clk, data->dev_name, data->gate_name);
>>> +
>>> +ÂÂÂÂÂÂÂ /* configure initial clock parent and state */
>>> +ÂÂÂÂÂÂÂ parent = clk_get_sys(data->gate_name,
>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ data->parents[data->init_parent_index]);
>>> +ÂÂÂÂÂÂÂ if (!IS_ERR(parent)) {
>>> +ÂÂÂÂÂÂÂÂÂÂÂ ret = clk_set_parent(clkmux, parent);
>>> +ÂÂÂÂÂÂÂÂÂÂÂ if (ret < 0) {
>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ pr_err("failed to set parent of %s to %s\n",
>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ __func__, __clk_get_name(clkmux),
>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ __clk_get_name(parent));
>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ WARN_ON(1);
>>> +ÂÂÂÂÂÂÂÂÂÂÂ }
>>> +ÂÂÂÂÂÂÂ }
>>> +
>>> +ÂÂÂÂÂÂÂ if (data->init_state) {
>>> +ÂÂÂÂÂÂÂÂÂÂÂ if (clk_prepare_enable(clk)) {
>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ pr_err("failed to enable %s\n", __func__,
>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ __clk_get_name(clk));
>>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ WARN_ON(1);

Alternatively you could write it like this:

err = clk_prepare_enable(clk);

WARN_ON(err, "failed to enable %s: %d\n",
__clk_get_name(clk), err);

>> Should be a bit better to move the WARN_ON to the end of errors handling
>> in order to catch all possible errors:
>>
>> @@ -2510,6 +2510,7 @@ static void tegra_pmc_clock_register(struct
>> tegra_pmc *pmc,
>> ÂÂÂÂÂÂÂÂ return;
>>
>> Â free_clks:
>> +ÂÂÂÂÂÂ WARN_ON(1);
>> ÂÂÂÂÂÂÂÂ kfree(clk_data->clks);
>> Â free_clkdata:
>> ÂÂÂÂÂÂÂÂ kfree(clk_data);
>
> Reason I had WARN_ON right during clk_set_parent failure is to have the
> loop continue for subsequence pmc clocks registration instead of
> terminating all pmc clocks registration.

Ah, okay. Nevertheless this WARN_ON in the end shouldn't be the least (IMO).