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[79.139.233.37]) by smtp.googlemail.com with ESMTPSA id y192sm243599lfa.63.2019.12.02.13.50.53 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 02 Dec 2019 13:50:54 -0800 (PST) Subject: Re: [PATCH v2 02/11] soc: tegra: Add Tegra PMC clock registrations into PMC driver To: Sowjanya Komatineni , thierry.reding@gmail.com, jonathanh@nvidia.com, mperttunen@nvidia.com, gregkh@linuxfoundation.org, sboyd@kernel.org, tglx@linutronix.de, robh+dt@kernel.org, mark.rutland@arm.com Cc: allison@lohutok.net, pdeschrijver@nvidia.com, pgaikwad@nvidia.com, mturquette@baylibre.com, horms+renesas@verge.net.au, Jisheng.Zhang@synaptics.com, krzk@kernel.org, arnd@arndb.de, spujar@nvidia.com, josephl@nvidia.com, vidyas@nvidia.com, daniel.lezcano@linaro.org, mmaddireddy@nvidia.com, markz@nvidia.com, devicetree@vger.kernel.org, linux-clk@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org References: <1574830773-14892-1-git-send-email-skomatineni@nvidia.com> <1574830773-14892-3-git-send-email-skomatineni@nvidia.com> <749de44c-ec59-3cab-c02e-7b8fcb1fb9f4@gmail.com> <3d1492a1-f2a5-2d56-5341-a28fcb73fe64@nvidia.com> <484cb1bb-4fb2-9e71-87be-2bd5bd5b2348@gmail.com> From: Dmitry Osipenko Message-ID: Date: Tue, 3 Dec 2019 00:50:52 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 02.12.2019 23:09, Sowjanya Komatineni пишет: > > On 11/28/19 5:25 AM, Dmitry Osipenko wrote: >> 28.11.2019 01:57, Sowjanya Komatineni пишет: >>> On 11/27/19 7:14 AM, Dmitry Osipenko wrote: >>>> 27.11.2019 07:59, Sowjanya Komatineni пишет: >>>>> 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 >>>>> --- >>>>>    drivers/soc/tegra/pmc.c | 330 >>>>> ++++++++++++++++++++++++++++++++++++++++++++++++ >>>>>    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 @@ >>>>>      #include >>>>>    #include >>>>> +#include >>>>> +#include >>>>> +#include >>>>>    #include >>>>>    #include >>>>>    #include >>>>> @@ -48,6 +51,7 @@ >>>>>    #include >>>>>    #include >>>>>    #include >>>>> +#include >>>>>      #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 +160,91 @@ >>>>>    #define  TEGRA_SMC_PMC_READ    0xaa >>>>>    #define  TEGRA_SMC_PMC_WRITE    0xbb >>>>>    +struct pmc_clk_mux { >>>>> +    struct clk_hw    hw; >>>>> +    unsigned long    offs; >>>>> +    u32        mask; >>>>> +    u32        shift; >>>>> +}; >>>>> + >>>>> +#define to_pmc_clk_mux(_hw) container_of(_hw, struct pmc_clk_mux, hw) >>>>> + >>>>> +struct pmc_clk_gate { >>>>> +    struct clk_hw    hw; >>>>> +    unsigned long    offs; >>>>> +    u32        shift; >>>>> +}; >>>>> + >>>>> +#define to_pmc_clk_gate(_hw) container_of(_hw, struct >>>>> pmc_clk_gate, hw) >>>>> + >>>>> +struct pmc_clk_init_data { >>>>> +    char *mux_name; >>>>> +    char *gate_name; >>>>> +    const char **parents; >>>>> +    int num_parents; >>>>> +    int mux_id; >>>>> +    int gate_id; >>>>> +    char *dev_name; >>>>> +    u8 mux_shift; >>>>> +    u8 gate_shift; >>>>> +    u8 init_parent_index; >>>>> +    int init_state; >>>>> +}; >>>>> + >>>>> +static const char *clk_out1_parents[] = { "clk_m", "clk_m_div2", >>>>> +    "clk_m_div4", "extern1", >>>>> +}; >>>>> + >>>>> +static const char *clk_out2_parents[] = { "clk_m", "clk_m_div2", >>>>> +    "clk_m_div4", "extern2", >>>>> +}; >>>>> + >>>>> +static const char *clk_out3_parents[] = { "clk_m", "clk_m_div2", >>>>> +    "clk_m_div4", "extern3", >>>>> +}; >>>>> + >>>>> +static struct pmc_clk_init_data tegra_pmc_clks_data[] = { >>>>> +    { >>>>> +        .mux_name = "clk_out_1_mux", >>>>> +        .gate_name = "clk_out_1", >>>>> +        .parents = clk_out1_parents, >>>>> +        .num_parents = ARRAY_SIZE(clk_out1_parents), >>>>> +        .mux_id = TEGRA_PMC_CLK_OUT_1_MUX, >>>>> +        .gate_id = TEGRA_PMC_CLK_OUT_1, >>>>> +        .dev_name = "extern1", >>>>> +        .mux_shift = 6, >>>>> +        .gate_shift = 2, >>>>> +        .init_parent_index = 3, >>>>> +        .init_state = 1, >>>>> +    }, >>>>> +    { >>>>> +        .mux_name = "clk_out_2_mux", >>>>> +        .gate_name = "clk_out_2", >>>>> +        .parents = clk_out2_parents, >>>>> +        .num_parents = ARRAY_SIZE(clk_out2_parents), >>>>> +        .mux_id = TEGRA_PMC_CLK_OUT_2_MUX, >>>>> +        .gate_id = TEGRA_PMC_CLK_OUT_2, >>>>> +        .dev_name = "extern2", >>>>> +        .mux_shift = 14, >>>>> +        .gate_shift = 10, >>>>> +        .init_parent_index = 0, >>>>> +        .init_state = 0, >>>>> +    }, >>>>> +    { >>>>> +        .mux_name = "clk_out_3_mux", >>>>> +        .gate_name = "clk_out_3", >>>>> +        .parents = clk_out3_parents, >>>>> +        .num_parents = ARRAY_SIZE(clk_out3_parents), >>>>> +        .mux_id = TEGRA_PMC_CLK_OUT_3_MUX, >>>>> +        .gate_id = TEGRA_PMC_CLK_OUT_3, >>>>> +        .dev_name = "extern3", >>>>> +        .mux_shift = 22, >>>>> +        .gate_shift = 18, >>>>> +        .init_parent_index = 0, >>>>> +        .init_state = 0, >>>>> +    }, >>>>> +}; >>>>> + >>>>>    struct tegra_powergate { >>>>>        struct generic_pm_domain genpd; >>>>>        struct tegra_pmc *pmc; >>>>> @@ -254,6 +344,9 @@ struct tegra_pmc_soc { >>>>>         */ >>>>>        const struct tegra_wake_event *wake_events; >>>>>        unsigned int num_wake_events; >>>>> + >>>>> +    struct pmc_clk_init_data *pmc_clks_data; >>>>> +    unsigned int num_pmc_clks; >>>>>    }; >>>>>      static const char * const tegra186_reset_sources[] = { >>>>> @@ -2163,6 +2256,228 @@ 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_mux *mux = to_pmc_clk_mux(hw); >>>>> +    int num_parents = clk_hw_get_num_parents(hw); >>>>> +    u32 val; >>>>> + >>>>> +    val = tegra_pmc_readl(pmc, mux->offs) >> mux->shift; >>>>> +    val &= mux->mask; >>>>> + >>>>> +    if (val >= num_parents) >>>>> +        return -EINVAL; >>>>> + >>>>> +    return val; >>>>> +} >>>>> + >>>>> +static int pmc_clk_mux_set_parent(struct clk_hw *hw, u8 index) >>>>> +{ >>>>> +    struct pmc_clk_mux *mux = to_pmc_clk_mux(hw); >>>>> +    u32 val; >>>>> + >>>>> +    val = tegra_pmc_readl(pmc, mux->offs); >>>>> +    val &= ~(mux->mask << mux->shift); >>>>> +    val |= index << mux->shift; >>>>> +    tegra_pmc_writel(pmc, val, mux->offs); >>>>> +    pmc_clk_fence_udelay(mux->offs); >>>>> + >>>>> +    return 0; >>>>> +} >>>>> + >>>>> +static const struct clk_ops pmc_clk_mux_ops = { >>>>> +    .get_parent = pmc_clk_mux_get_parent, >>>>> +    .set_parent = pmc_clk_mux_set_parent, >>>>> +    .determine_rate = __clk_mux_determine_rate, >>>>> +}; >>>>> + >>>>> +static struct clk * >>>>> +tegra_pmc_clk_mux_register(const char *name, const char * const >>>>> *parent_names, >>>>> +               int num_parents, unsigned long flags, >>>>> +               unsigned long offset, u32 shift, u32 mask) >>>>> +{ >>>>> +    struct clk_init_data init; >>>>> +    struct pmc_clk_mux *mux; >>>>> + >>>>> +    mux = kzalloc(sizeof(*mux), GFP_KERNEL); >>>>> +    if (!mux) >>>>> +        return ERR_PTR(-ENOMEM); >>>>> + >>>>> +    init.name = name; >>>>> +    init.ops = &pmc_clk_mux_ops; >>>>> +    init.parent_names = parent_names; >>>>> +    init.num_parents = num_parents; >>>>> +    init.flags = flags; >>>>> + >>>>> +    mux->hw.init = &init; >>>>> +    mux->offs = offset; >>>>> +    mux->mask = mask; >>>>> +    mux->shift = shift; >>>>> + >>>>> +    return clk_register(NULL, &mux->hw); >>>>> +} >>>>> + >>>>> +static int pmc_clk_is_enabled(struct clk_hw *hw) >>>>> +{ >>>>> +    struct pmc_clk_gate *gate = to_pmc_clk_gate(hw); >>>>> + >>>>> +    return tegra_pmc_readl(pmc, gate->offs) & BIT(gate->shift) ? 1 >>>>> : 0; >>>>> +} >>>>> + >>>>> +static void pmc_clk_set_state(struct clk_hw *hw, int state) >>>>> +{ >>>>> +    struct pmc_clk_gate *gate = to_pmc_clk_gate(hw); >>>>> +    u32 val; >>>>> + >>>>> +    val = tegra_pmc_readl(pmc, gate->offs); >>>>> +    val = state ? (val | BIT(gate->shift)) : (val & >>>>> ~BIT(gate->shift)); >>>>> +    tegra_pmc_writel(pmc, val, gate->offs); >>>>> +    pmc_clk_fence_udelay(gate->offs); >>>>> +} >>>>> + >>>>> +static int pmc_clk_enable(struct clk_hw *hw) >>>>> +{ >>>>> +    pmc_clk_set_state(hw, 1); >>>>> + >>>>> +    return 0; >>>>> +} >>>>> + >>>>> +static void pmc_clk_disable(struct clk_hw *hw) >>>>> +{ >>>>> +    pmc_clk_set_state(hw, 0); >>>>> +} >>>>> + >>>>> +static const struct clk_ops pmc_clk_gate_ops = { >>>>> +    .is_enabled = pmc_clk_is_enabled, >>>>> +    .enable = pmc_clk_enable, >>>>> +    .disable = pmc_clk_disable, >>>>> +}; >>>>> + >>>>> +static struct clk * >>>>> +tegra_pmc_clk_gate_register(const char *name, const char >>>>> *parent_name, >>>>> +                unsigned long flags, unsigned long offset, >>>>> +                u32 shift) >>>>> +{ >>>>> +    struct clk_init_data init; >>>>> +    struct pmc_clk_gate *gate; >>>>> + >>>>> +    gate = kzalloc(sizeof(*gate), GFP_KERNEL); >>>>> +    if (!gate) >>>>> +        return ERR_PTR(-ENOMEM); >>>>> + >>>>> +    init.name = name; >>>>> +    init.ops = &pmc_clk_gate_ops; >>>>> +    init.parent_names = &parent_name; >>>>> +    init.num_parents = 1; >>>>> +    init.flags = flags; >>>>> + >>>>> +    gate->hw.init = &init; >>>>> +    gate->offs = offset; >>>>> +    gate->shift = shift; >>>>> + >>>>> +    return clk_register(NULL, &gate->hw); >>>>> +} >>>>> + >>>>> +static void tegra_pmc_clock_register(struct tegra_pmc *pmc, >>>>> +                     struct device_node *np) >>>>> +{ >>>>> +    struct clk *clkmux, *clk, *parent; >>>>> +    struct clk_onecell_data *clk_data; >>>>> +    unsigned int num_clks; >>>>> +    int i, ret; >>>>> + >>>>> +    /* each pmc clock output has a mux and a gate */ >>>>> +    num_clks = pmc->soc->num_pmc_clks * 2; >>>>> + >>>>> +    if (!num_clks) >>>>> +        return; >>>>> + >>>>> +    clk_data = kmalloc(sizeof(*clk_data), GFP_KERNEL); >>>>> +    if (!clk_data) >>>>> +        return; >>>>> + >>>>> +    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 = num_clks; >>>>> + >>>>> +    for (i = 0; i < pmc->soc->num_pmc_clks; i++) { >>>>> +        struct pmc_clk_init_data *data; >>>>> + >>>>> +        data = pmc->soc->pmc_clks_data + i; >>>>> + >>>>> +        clkmux = tegra_pmc_clk_mux_register(data->mux_name, >>>>> +                            data->parents, >>>>> +                            data->num_parents, >>>>> +                            CLK_SET_RATE_NO_REPARENT | >>>>> +                            CLK_SET_RATE_PARENT, >>>>> +                            PMC_CLK_OUT_CNTRL, >>>>> +                            data->mux_shift, 3); >>>>> +        if (IS_ERR(clkmux)) >>>>> +            goto free_clks; >>>>> + >>>>> +        clk_data->clks[data->mux_id] = clkmux; >>>>> + >>>>> +        clk = tegra_pmc_clk_gate_register(data->gate_name, >>>>> +                          data->mux_name, >>>>> +                          CLK_SET_RATE_PARENT, >>>>> +                          PMC_CLK_OUT_CNTRL, >>>>> +                          data->gate_shift); >>>>> +        if (IS_ERR(clk)) >>>>> +            goto free_clks; >>>>> + >>>>> +        clk_data->clks[data->gate_id] = clk; >>>>> + >>>>> +        ret = clk_set_parent(clk, clkmux); >>>>> +        if (ret < 0) { >>>>> +            pr_err("failed to set parent of %s to %s\n", >>>>> +                   __func__, __clk_get_name(clk), >>>>> +                   __clk_get_name(clkmux)); >>>>> +        } >>>>> + >>>>> +        clk_register_clkdev(clk, data->dev_name, data->gate_name); >>>>> + >>>>> +        /* configure initial clock parent and state */ >>>>> +        parent = clk_get_sys(data->gate_name, >>>>> +                     data->parents[data->init_parent_index]); Couldn't the default parent be defined using "assigned clock" in a device-tree? Please see "Assigned clock parents and rates" in the doc. https://www.kernel.org/doc/Documentation/devicetree/bindings/clock/clock-bindings.txt Then you could simply use of_clk_set_defaults(pmc->dev->of_node, true). >>>>> +        if (!IS_ERR(parent)) { >>>>> +            ret = clk_set_parent(clkmux, parent); >>>>> +            if (ret < 0) { >>>>> +                pr_err("failed to set parent of %s to %s\n", >>>>> +                       __func__, __clk_get_name(clkmux), >>>>> +                       __clk_get_name(parent)); >>>>> +                WARN_ON(1); >>>>> +            } >>>>> +        } >>>>> + >>>>> +        if (data->init_state) { >>>>> +            if (clk_prepare_enable(clk)) { >>>>> +                pr_err("failed to enable %s\n", __func__, >>>>> +                       __clk_get_name(clk)); >>>>> +                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, >>>>           return; >>>> >>>>    free_clks: >>>> +       WARN_ON(1); >>>>           kfree(clk_data->clks); >>>>    free_clkdata: >>>>           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). > Hi Dmitry, Just want to be clear on the above comment. Are you > suggesting to add additional WARN_ON at the end? Yes, it was my suggestion. > Thought WARN_ON right during corresponding clock failure with warn > message showing clock names will be clear and also other clocks still > should be registered. > > To add additional WARN_ON at the end need to track status of each clock > and use that to as warn condition. You could add a warning/error message to every point of failure. Primarily, it is important not to miss a error. Secondarily, it is important to make diagnostic message meaningful. Realistically, I doubt that this chunk of code will ever fail once it is known to work well. So it will be nice to have a more detailed diagnostics (just in a case), but it shouldn't be a must.