Commit 156c5887 authored by Hans de Goede's avatar Hans de Goede Committed by Tejun Heo
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ahci-platform: Add support for devices with more then 1 clock 



The allwinner-sun4i AHCI controller needs 2 clocks to be enabled and the
imx AHCI controller needs 3 clocks to be enabled.

tj: Minor comment formatting updates.

Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 039ece38

Documentation/devicetree/bindings/ata/ahci-platform.txt

+1 −0
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ Required properties: 


Optional properties:

- dma-coherent      : Present if dma operations are coherent

- clocks            : a list of phandle + clock specifier pairs



Example:

        sata@ffe08000 {

drivers/ata/ahci.h

+2 −1
Original line number Diff line number Diff line
@@ -51,6 +51,7 @@ 


enum {

	AHCI_MAX_PORTS		= 32,

	AHCI_MAX_CLKS		= 3,

	AHCI_MAX_SG		= 168, /* hardware max is 64K */

	AHCI_DMA_BOUNDARY	= 0xffffffff,

	AHCI_MAX_CMDS		= 32,
@@ -321,7 +322,7 @@ struct ahci_host_priv { 
	u32 			em_loc; /* enclosure management location */

	u32			em_buf_sz;	/* EM buffer size in byte */

	u32			em_msg_type;	/* EM message type */

	struct clk		*clk;		/* Only for platforms supporting clk */

	struct clk		*clks[AHCI_MAX_CLKS]; /* Optional */

	void			*plat_data;	/* Other platform data */

	/*

	 * Optional ahci_start_engine override, if not set this gets set to the

drivers/ata/ahci_platform.c

+86 −27
Original line number Diff line number Diff line
@@ -86,6 +86,60 @@ static struct scsi_host_template ahci_platform_sht = { 
	AHCI_SHT("ahci_platform"),

};



/**

 * ahci_platform_enable_clks - Enable platform clocks

 * @hpriv: host private area to store config values

 *

 * This function enables all the clks found in hpriv->clks, starting at

 * index 0. If any clk fails to enable it disables all the clks already

 * enabled in reverse order, and then returns an error.

 *

 * RETURNS:

 * 0 on success otherwise a negative error code

 */

int ahci_platform_enable_clks(struct ahci_host_priv *hpriv)

{

	int c, rc;



	for (c = 0; c < AHCI_MAX_CLKS && hpriv->clks[c]; c++) {

		rc = clk_prepare_enable(hpriv->clks[c]);

		if (rc)

			goto disable_unprepare_clk;

	}

	return 0;



disable_unprepare_clk:

	while (--c >= 0)

		clk_disable_unprepare(hpriv->clks[c]);

	return rc;

}

EXPORT_SYMBOL_GPL(ahci_platform_enable_clks);



/**

 * ahci_platform_disable_clks - Disable platform clocks

 * @hpriv: host private area to store config values

 *

 * This function disables all the clks found in hpriv->clks, in reverse

 * order of ahci_platform_enable_clks (starting at the end of the array).

 */

void ahci_platform_disable_clks(struct ahci_host_priv *hpriv)

{

	int c;



	for (c = AHCI_MAX_CLKS - 1; c >= 0; c--)

		if (hpriv->clks[c])

			clk_disable_unprepare(hpriv->clks[c]);

}

EXPORT_SYMBOL_GPL(ahci_platform_disable_clks);



static void ahci_put_clks(struct ahci_host_priv *hpriv)

{

	int c;



	for (c = 0; c < AHCI_MAX_CLKS && hpriv->clks[c]; c++)

		clk_put(hpriv->clks[c]);

}



static int ahci_probe(struct platform_device *pdev)

{

	struct device *dev = &pdev->dev;
@@ -96,6 +150,7 @@ static int ahci_probe(struct platform_device *pdev) 
	struct ahci_host_priv *hpriv;

	struct ata_host *host;

	struct resource *mem;

	struct clk *clk;

	int irq;

	int n_ports;

	int i;
@@ -130,17 +185,31 @@ static int ahci_probe(struct platform_device *pdev) 
		return -ENOMEM;

	}



	hpriv->clk = clk_get(dev, NULL);

	if (IS_ERR(hpriv->clk)) {

		dev_err(dev, "can't get clock\n");

	} else {

		rc = clk_prepare_enable(hpriv->clk);

		if (rc) {

			dev_err(dev, "clock prepare enable failed");

	for (i = 0; i < AHCI_MAX_CLKS; i++) {

		/*

		 * For now we must use clk_get(dev, NULL) for the first clock,

		 * because some platforms (da850, spear13xx) are not yet

		 * converted to use devicetree for clocks.  For new platforms

		 * this is equivalent to of_clk_get(dev->of_node, 0).

		 */

		if (i == 0)

			clk = clk_get(dev, NULL);

		else

			clk = of_clk_get(dev->of_node, i);



		if (IS_ERR(clk)) {

			rc = PTR_ERR(clk);

			if (rc == -EPROBE_DEFER)

				goto free_clk;

			break;

		}

		hpriv->clks[i] = clk;

	}



	rc = ahci_enable_clks(dev, hpriv);

	if (rc)

		goto free_clk;



	/*

	 * Some platforms might need to prepare for mmio region access,

	 * which could be done in the following init call. So, the mmio
@@ -221,11 +290,9 @@ pdata_exit: 
	if (pdata && pdata->exit)

		pdata->exit(dev);

disable_unprepare_clk:

	if (!IS_ERR(hpriv->clk))

		clk_disable_unprepare(hpriv->clk);

	ahci_disable_clks(hpriv);

free_clk:

	if (!IS_ERR(hpriv->clk))

		clk_put(hpriv->clk);

	ahci_put_clks(hpriv);

	return rc;

}
@@ -238,10 +305,8 @@ static void ahci_host_stop(struct ata_host *host) 
	if (pdata && pdata->exit)

		pdata->exit(dev);



	if (!IS_ERR(hpriv->clk)) {

		clk_disable_unprepare(hpriv->clk);

		clk_put(hpriv->clk);

	}

	ahci_disable_clks(hpriv);

	ahci_put_clks(hpriv);

}



#ifdef CONFIG_PM_SLEEP
@@ -276,8 +341,7 @@ static int ahci_suspend(struct device *dev) 
	if (pdata && pdata->suspend)

		return pdata->suspend(dev);



	if (!IS_ERR(hpriv->clk))

		clk_disable_unprepare(hpriv->clk);

	ahci_disable_clks(hpriv);



	return 0;

}
@@ -289,13 +353,9 @@ static int ahci_resume(struct device *dev) 
	struct ahci_host_priv *hpriv = host->private_data;

	int rc;



	if (!IS_ERR(hpriv->clk)) {

		rc = clk_prepare_enable(hpriv->clk);

		if (rc) {

			dev_err(dev, "clock prepare enable failed");

	rc = ahci_enable_clks(dev, hpriv);

	if (rc)

		return rc;

		}

	}



	if (pdata && pdata->resume) {

		rc = pdata->resume(dev);
@@ -316,8 +376,7 @@ static int ahci_resume(struct device *dev) 
	return 0;



disable_unprepare_clk:

	if (!IS_ERR(hpriv->clk))

		clk_disable_unprepare(hpriv->clk);

	ahci_disable_clks(hpriv);



	return rc;

}

include/linux/ahci_platform.h

+4 −0
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ 


struct device;

struct ata_port_info;

struct ahci_host_priv;



struct ahci_platform_data {

	int (*init)(struct device *dev, void __iomem *addr);
@@ -30,4 +31,7 @@ struct ahci_platform_data { 
	unsigned int mask_port_map;

};



int ahci_platform_enable_clks(struct ahci_host_priv *hpriv);

void ahci_platform_disable_clks(struct ahci_host_priv *hpriv);



#endif /* _AHCI_PLATFORM_H */

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