Commit 97904a59 authored by Kamal Dasu's avatar Kamal Dasu Committed by Ulf Hansson
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mmc: sdhci-brcmstb: Add ability to increase max clock rate for 72116b0 



The 72116B0 has improved SDIO controllers that allow the max clock
rate to be increased from a max of 100MHz to a max of 150MHz. The
driver will need to get the clock and increase it's default rate
and override the caps register, that still indicates a max of 100MHz.
The new clock will be named "sdio_freq" in the DT node's "clock-names"
list. The driver will use a DT property, "clock-frequency", to
enable this functionality and will get the actual rate in MHz
from the property to allow various speeds to be requested.

Signed-off-by: default avatarAl Cooper <alcooperx@gmail.com>
Signed-off-by: default avatarKamal Dasu <kdasu.kdev@gmail.com>
Acked-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20220520183108.47358-3-kdasu.kdev@gmail.com


Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent 2f8690ef

drivers/mmc/host/sdhci-brcmstb.c

+68 −1
Original line number Diff line number Diff line
@@ -31,6 +31,8 @@ 
struct sdhci_brcmstb_priv {

	void __iomem *cfg_regs;

	unsigned int flags;

	struct clk *base_clk;

	u32 base_freq_hz;

};



struct brcmstb_match_priv {
@@ -250,9 +252,11 @@ static int sdhci_brcmstb_probe(struct platform_device *pdev) 
	struct sdhci_pltfm_host *pltfm_host;

	const struct of_device_id *match;

	struct sdhci_brcmstb_priv *priv;

	u32 actual_clock_mhz;

	struct sdhci_host *host;

	struct resource *iomem;

	struct clk *clk;

	struct clk *base_clk;

	int res;



	match = of_match_node(sdhci_brcm_of_match, pdev->dev.of_node);
@@ -330,6 +334,35 @@ static int sdhci_brcmstb_probe(struct platform_device *pdev) 
	if (match_priv->flags & BRCMSTB_MATCH_FLAGS_BROKEN_TIMEOUT)

		host->quirks |= SDHCI_QUIRK_BROKEN_TIMEOUT_VAL;



	/* Change the base clock frequency if the DT property exists */

	if (device_property_read_u32(&pdev->dev, "clock-frequency",

				     &priv->base_freq_hz) != 0)

		goto add_host;



	base_clk = devm_clk_get_optional(&pdev->dev, "sdio_freq");

	if (IS_ERR(base_clk)) {

		dev_warn(&pdev->dev, "Clock for \"sdio_freq\" not found\n");

		goto add_host;

	}



	res = clk_prepare_enable(base_clk);

	if (res)

		goto err;



	/* set improved clock rate */

	clk_set_rate(base_clk, priv->base_freq_hz);

	actual_clock_mhz = clk_get_rate(base_clk) / 1000000;



	host->caps &= ~SDHCI_CLOCK_V3_BASE_MASK;

	host->caps |= (actual_clock_mhz << SDHCI_CLOCK_BASE_SHIFT);

	/* Disable presets because they are now incorrect */

	host->quirks2 |= SDHCI_QUIRK2_PRESET_VALUE_BROKEN;



	dev_dbg(&pdev->dev, "Base Clock Frequency changed to %dMHz\n",

		actual_clock_mhz);

	priv->base_clk = base_clk;



add_host:

	res = sdhci_brcmstb_add_host(host, priv);

	if (res)

		goto err;
@@ -340,6 +373,7 @@ static int sdhci_brcmstb_probe(struct platform_device *pdev) 
err:

	sdhci_pltfm_free(pdev);

err_clk:

	clk_disable_unprepare(base_clk);

	clk_disable_unprepare(clk);

	return res;

}
@@ -351,11 +385,44 @@ static void sdhci_brcmstb_shutdown(struct platform_device *pdev) 


MODULE_DEVICE_TABLE(of, sdhci_brcm_of_match);



#ifdef CONFIG_PM_SLEEP

static int sdhci_brcmstb_suspend(struct device *dev)

{

	struct sdhci_host *host = dev_get_drvdata(dev);

	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);

	struct sdhci_brcmstb_priv *priv = sdhci_pltfm_priv(pltfm_host);



	clk_disable_unprepare(priv->base_clk);

	return sdhci_pltfm_suspend(dev);

}



static int sdhci_brcmstb_resume(struct device *dev)

{

	struct sdhci_host *host = dev_get_drvdata(dev);

	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);

	struct sdhci_brcmstb_priv *priv = sdhci_pltfm_priv(pltfm_host);

	int ret;



	ret = sdhci_pltfm_resume(dev);

	if (!ret && priv->base_freq_hz) {

		ret = clk_prepare_enable(priv->base_clk);

		if (!ret)

			ret = clk_set_rate(priv->base_clk, priv->base_freq_hz);

	}



	return ret;

}

#endif



static const struct dev_pm_ops sdhci_brcmstb_pmops = {

	SET_SYSTEM_SLEEP_PM_OPS(sdhci_brcmstb_suspend, sdhci_brcmstb_resume)

};



static struct platform_driver sdhci_brcmstb_driver = {

	.driver		= {

		.name	= "sdhci-brcmstb",

		.probe_type = PROBE_PREFER_ASYNCHRONOUS,

		.pm	= &sdhci_pltfm_pmops,

		.pm	= &sdhci_brcmstb_pmops,

		.of_match_table = of_match_ptr(sdhci_brcm_of_match),

	},

	.probe		= sdhci_brcmstb_probe,