From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bjorn Andersson Subject: Re: [PATCH v3 3/9] mmc: sdhci-msm: add pltfm_data support to get clk-rates from DT Date: Mon, 22 Aug 2016 21:31:21 -0700 Message-ID: <20160823043121.GC26240@tuxbot> References: <1471581384-18961-1-git-send-email-riteshh@codeaurora.org> <1471581384-18961-4-git-send-email-riteshh@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1471581384-18961-4-git-send-email-riteshh@codeaurora.org> Sender: linux-mmc-owner@vger.kernel.org To: Ritesh Harjani Cc: adrian.hunter@intel.com, ulf.hansson@linaro.org, shawn.lin@rock-chips.com, jh80.chung@samsung.com, linux-mmc@vger.kernel.org, linux-arm-msm@vger.kernel.org, georgi.djakov@linaro.org, alex.lemberg@sandisk.com, mateusz.nowak@intel.com, Yuliy.Izrailov@sandisk.com, asutoshd@codeaurora.org, kdorfman@codeaurora.org, david.griego@linaro.org, stummala@codeaurora.org, venkatg@codeaurora.org List-Id: linux-arm-msm@vger.kernel.org On Thu 18 Aug 21:36 PDT 2016, Ritesh Harjani wrote: > This adds support for sdhc-msm controllers to get supported > clk-rates from DT. sdhci-msm would need it's own set_clock > ops to be implemented. For this, supported clk-rates needs > to be populated in sdhci_msm_pltfm_data. > > Signed-off-by: Ritesh Harjani > --- > .../devicetree/bindings/mmc/sdhci-msm.txt | 1 + > drivers/mmc/host/sdhci-msm.c | 71 ++++++++++++++++++++++ > 2 files changed, 72 insertions(+) > > diff --git a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt > index 485483a..6a83b38 100644 > --- a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt > +++ b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt > @@ -17,6 +17,7 @@ Required properties: > "iface" - Main peripheral bus clock (PCLK/HCLK - AHB Bus clock) (required) > "core" - SDC MMC clock (MCLK) (required) > "bus" - SDCC bus voter clock (optional) > +- clk-rates: Array of supported GCC clock frequencies for sdhc, Units - Hz. > > Example: > > diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c > index 85ddaae..2bf141b 100644 > --- a/drivers/mmc/host/sdhci-msm.c > +++ b/drivers/mmc/host/sdhci-msm.c > @@ -74,6 +74,11 @@ > #define CMUX_SHIFT_PHASE_SHIFT 24 > #define CMUX_SHIFT_PHASE_MASK (7 << CMUX_SHIFT_PHASE_SHIFT) > > +struct sdhci_msm_pltfm_data { > + u32 *clk_table; > + size_t clk_table_sz; > +}; Rather than calling this "platform data", just call it sdhci_msm_freq_table and make it: struct sdhci_msm_freq_table { size_t num_freqs; u32 freqs[]; }; > + > struct sdhci_msm_host { > struct platform_device *pdev; > void __iomem *core_mem; /* MSM SDCC mapped address */ > @@ -83,6 +88,7 @@ struct sdhci_msm_host { > struct clk *bus_clk; /* SDHC bus voter clock */ > struct mmc_host *mmc; > bool use_14lpp_dll_reset; > + struct sdhci_msm_pltfm_data *pdata; > }; > > /* Platform specific tuning */ > @@ -582,6 +588,67 @@ static const struct sdhci_pltfm_data sdhci_msm_pdata = { > .ops = &sdhci_msm_ops, > }; > > +static int sdhci_msm_dt_get_array(struct device *dev, const char *prop_name, > + u32 **table, size_t *size) > +{ > + struct device_node *np = dev->of_node; > + int count = 0; > + u32 *arr = NULL; > + int ret = 0; > + > + count = of_property_count_elems_of_size(np, prop_name, sizeof(u32)); > + if (count < 0) { > + dev_err(dev, "%s: Invalid dt property, err(%d)\n", > + prop_name, count); > + ret = count; > + goto out; > + } > + > + arr = devm_kzalloc(dev, count * sizeof(*arr), GFP_KERNEL); > + if (!arr) { > + ret = -ENOMEM; > + goto out; > + } > + > + ret = of_property_read_u32_array(np, prop_name, arr, count); > + if (ret) { > + dev_err(dev, "%s Invalid dt array property, err(%d)\n", > + prop_name, ret); > + goto out; > + } > + *table = arr; > + *size = count; > +out: > + return ret; > +} > + > +static struct sdhci_msm_pltfm_data *sdhci_msm_populate_pdata(struct device *dev, > + struct sdhci_msm_host *msm_host) > +{ > + struct sdhci_msm_pltfm_data *pdata = NULL; > + size_t table_sz = 0; > + u32 *table = NULL; > + Count of_property_count_elems_of_size() here and then allocate sizeof(*tbl) + count * sizeof(tbl->freqs[0]) and fill that in, no need for the two allocations. > + pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); > + if (!pdata) > + goto out; No need for a goto for early errors, just return as you haven't touch any state yet. > + > + if (sdhci_msm_dt_get_array(dev, "clk-rates", &table, &table_sz)) { > + dev_err(dev, "failed in DT parsing for supported clk-rates\n"); > + goto out; > + } > + if (!table || !table_sz) { A general comment; don't be too defensive in your code. Neither table nor table_sz should be able to be zero if the above condition fails... > + dev_err(dev, "Invalid clock table\n"); > + goto out; > + } > + pdata->clk_table = table; > + pdata->clk_table_sz = table_sz; > + > + return pdata; > +out: > + return NULL; > +} > + > static int sdhci_msm_probe(struct platform_device *pdev) > { > struct sdhci_host *host; > @@ -608,6 +675,10 @@ static int sdhci_msm_probe(struct platform_device *pdev) > > sdhci_get_of_property(pdev); > > + msm_host->pdata = sdhci_msm_populate_pdata(&pdev->dev, msm_host); > + if (!msm_host->pdata) > + goto pltfm_free; Adding this as a requirement breaks existing platforms/dtbs, you may force it for 8996 if you can detect that, but you should not change it for existing platforms. > + > /* Setup SDCC bus voter clock. */ > msm_host->bus_clk = devm_clk_get(&pdev->dev, "bus"); > if (!IS_ERR(msm_host->bus_clk)) { Regards, Bjorn