[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <664f1a41-d539-36e8-092b-11d7e4555108@nvidia.com>
Date: Thu, 19 Dec 2019 17:21:35 -0800
From: Sowjanya Komatineni <skomatineni@...dia.com>
To: Dmitry Osipenko <digetx@...il.com>, <thierry.reding@...il.com>,
<jonathanh@...dia.com>, <mperttunen@...dia.com>,
<gregkh@...uxfoundation.org>, <sboyd@...nel.org>,
<robh+dt@...nel.org>, <mark.rutland@....com>
CC: <pdeschrijver@...dia.com>, <pgaikwad@...dia.com>,
<spujar@...dia.com>, <josephl@...dia.com>,
<daniel.lezcano@...aro.org>, <mmaddireddy@...dia.com>,
<markz@...dia.com>, <devicetree@...r.kernel.org>,
<linux-clk@...r.kernel.org>, <linux-tegra@...r.kernel.org>,
<linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v4 06/19] soc: tegra: Add Tegra PMC clock registrations
into PMC driver
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@...dia.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)
>
> 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,
Powered by blists - more mailing lists