diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig index 0b5c87114369..5274f503a39a 100644 --- a/drivers/mmc/host/Kconfig +++ b/drivers/mmc/host/Kconfig @@ -122,6 +122,7 @@ config MMC_SDHCI_OF_ARASAN tristate "SDHCI OF support for the Arasan SDHCI controllers" depends on MMC_SDHCI_PLTFM depends on OF + depends on COMMON_CLK help This selects the Arasan Secure Digital Host Controller Interface (SDHCI). This hardware is found e.g. in Xilinx' Zynq SoC. diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c index 1286fe8905dc..678f316702e0 100644 --- a/drivers/mmc/host/sdhci-of-arasan.c +++ b/drivers/mmc/host/sdhci-of-arasan.c @@ -19,6 +19,7 @@ * your option) any later version. */ +#include #include #include #include @@ -73,17 +74,24 @@ struct sdhci_arasan_soc_ctl_map { /** * struct sdhci_arasan_data + * @host: Pointer to the main SDHCI host structure. * @clk_ahb: Pointer to the AHB clock * @phy: Pointer to the generic phy * @phy_on: True if the PHY is turned on. + * @sdcardclk_hw: Struct for the clock we might provide to a PHY. + * @sdcardclk: Pointer to normal 'struct clock' for sdcardclk_hw. * @soc_ctl_base: Pointer to regmap for syscon for soc_ctl registers. * @soc_ctl_map: Map to get offsets into soc_ctl registers. */ struct sdhci_arasan_data { + struct sdhci_host *host; struct clk *clk_ahb; struct phy *phy; bool phy_on; + struct clk_hw sdcardclk_hw; + struct clk *sdcardclk; + struct regmap *soc_ctl_base; const struct sdhci_arasan_soc_ctl_map *soc_ctl_map; }; @@ -306,6 +314,31 @@ static const struct of_device_id sdhci_arasan_of_match[] = { }; MODULE_DEVICE_TABLE(of, sdhci_arasan_of_match); +/** + * sdhci_arasan_sdcardclk_recalc_rate - Return the card clock rate + * + * Return the current actual rate of the SD card clock. This can be used + * to communicate with out PHY. + * + * @hw: Pointer to the hardware clock structure. + * @parent_rate The parent rate (should be rate of clk_xin). + * Returns the card clock rate. + */ +static unsigned long sdhci_arasan_sdcardclk_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) + +{ + struct sdhci_arasan_data *sdhci_arasan = + container_of(hw, struct sdhci_arasan_data, sdcardclk_hw); + struct sdhci_host *host = sdhci_arasan->host; + + return host->mmc->actual_clock; +} + +static const struct clk_ops arasan_sdcardclk_ops = { + .recalc_rate = sdhci_arasan_sdcardclk_recalc_rate, +}; + /** * sdhci_arasan_update_baseclkfreq - Set corecfg_baseclkfreq * @@ -345,6 +378,83 @@ static void sdhci_arasan_update_baseclkfreq(struct sdhci_host *host) sdhci_arasan_syscon_write(host, &soc_ctl_map->baseclkfreq, mhz); } +/** + * sdhci_arasan_register_sdclk - Register the sdclk for a PHY to use + * + * Some PHY devices need to know what the actual card clock is. In order for + * them to find out, we'll provide a clock through the common clock framework + * for them to query. + * + * Note: without seriously re-architecting SDHCI's clock code and testing on + * all platforms, there's no way to create a totally beautiful clock here + * with all clock ops implemented. Instead, we'll just create a clock that can + * be queried and set the CLK_GET_RATE_NOCACHE attribute to tell common clock + * framework that we're doing things behind its back. This should be sufficient + * to create nice clean device tree bindings and later (if needed) we can try + * re-architecting SDHCI if we see some benefit to it. + * + * @sdhci_arasan: Our private data structure. + * @clk_xin: Pointer to the functional clock + * @dev: Pointer to our struct device. + * Returns 0 on success and error value on error + */ +static int sdhci_arasan_register_sdclk(struct sdhci_arasan_data *sdhci_arasan, + struct clk *clk_xin, + struct device *dev) +{ + struct device_node *np = dev->of_node; + struct clk_init_data sdcardclk_init; + const char *parent_clk_name; + int ret; + + /* Providing a clock to the PHY is optional; no error if missing */ + if (!of_find_property(np, "#clock-cells", NULL)) + return 0; + + ret = of_property_read_string_index(np, "clock-output-names", 0, + &sdcardclk_init.name); + if (ret) { + dev_err(dev, "DT has #clock-cells but no clock-output-names\n"); + return ret; + } + + parent_clk_name = __clk_get_name(clk_xin); + sdcardclk_init.parent_names = &parent_clk_name; + sdcardclk_init.num_parents = 1; + sdcardclk_init.flags = CLK_GET_RATE_NOCACHE; + sdcardclk_init.ops = &arasan_sdcardclk_ops; + + sdhci_arasan->sdcardclk_hw.init = &sdcardclk_init; + sdhci_arasan->sdcardclk = + devm_clk_register(dev, &sdhci_arasan->sdcardclk_hw); + sdhci_arasan->sdcardclk_hw.init = NULL; + + ret = of_clk_add_provider(np, of_clk_src_simple_get, + sdhci_arasan->sdcardclk); + if (ret) + dev_err(dev, "Failed to add clock provider\n"); + + return ret; +} + +/** + * sdhci_arasan_unregister_sdclk - Undoes sdhci_arasan_register_sdclk() + * + * Should be called any time we're exiting and sdhci_arasan_register_sdclk() + * returned success. + * + * @dev: Pointer to our struct device. + */ +static void sdhci_arasan_unregister_sdclk(struct device *dev) +{ + struct device_node *np = dev->of_node; + + if (!of_find_property(np, "#clock-cells", NULL)) + return; + + of_clk_del_provider(dev->of_node); +} + static int sdhci_arasan_probe(struct platform_device *pdev) { int ret; @@ -362,6 +472,7 @@ static int sdhci_arasan_probe(struct platform_device *pdev) pltfm_host = sdhci_priv(host); sdhci_arasan = sdhci_pltfm_priv(pltfm_host); + sdhci_arasan->host = host; match = of_match_node(sdhci_arasan_of_match, pdev->dev.of_node); sdhci_arasan->soc_ctl_map = match->data; @@ -411,10 +522,14 @@ static int sdhci_arasan_probe(struct platform_device *pdev) sdhci_arasan_update_baseclkfreq(host); + ret = sdhci_arasan_register_sdclk(sdhci_arasan, clk_xin, &pdev->dev); + if (ret) + goto clk_disable_all; + ret = mmc_of_parse(host->mmc); if (ret) { dev_err(&pdev->dev, "parsing dt failed (%u)\n", ret); - goto clk_disable_all; + goto unreg_clk; } sdhci_arasan->phy = ERR_PTR(-ENODEV); @@ -425,13 +540,13 @@ static int sdhci_arasan_probe(struct platform_device *pdev) if (IS_ERR(sdhci_arasan->phy)) { ret = PTR_ERR(sdhci_arasan->phy); dev_err(&pdev->dev, "No phy for arasan,sdhci-5.1.\n"); - goto clk_disable_all; + goto unreg_clk; } ret = phy_init(sdhci_arasan->phy); if (ret < 0) { dev_err(&pdev->dev, "phy_init err.\n"); - goto clk_disable_all; + goto unreg_clk; } host->mmc_host_ops.hs400_enhanced_strobe = @@ -447,6 +562,8 @@ static int sdhci_arasan_probe(struct platform_device *pdev) err_add_host: if (!IS_ERR(sdhci_arasan->phy)) phy_exit(sdhci_arasan->phy); +unreg_clk: + sdhci_arasan_unregister_sdclk(&pdev->dev); clk_disable_all: clk_disable_unprepare(clk_xin); clk_dis_ahb: @@ -469,6 +586,8 @@ static int sdhci_arasan_remove(struct platform_device *pdev) phy_exit(sdhci_arasan->phy); } + sdhci_arasan_unregister_sdclk(&pdev->dev); + ret = sdhci_pltfm_unregister(pdev); clk_disable_unprepare(clk_ahb);