Commit dfd7f2c1 authored by Eddie James's avatar Eddie James Committed by Greg Kroah-Hartman
Browse files

fsi: Aspeed: Add mutex to protect HW access 



There is nothing to prevent multiple commands being executed
simultaneously. Add a mutex to prevent this.

Fixes: 606397d6 ("fsi: Add ast2600 master driver")
Reviewed-by: default avatarJoel Stanley <joel@jms.id.au>
Reviewed-by: default avatarMilton Miller <miltonm@us.ibm.com>
Signed-off-by: default avatarEddie James <eajames@linux.ibm.com>
Signed-off-by: default avatarJoel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20201120004929.185239-1-joel@jms.id.au


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent fe34761d

drivers/fsi/fsi-master-aspeed.c

+29 −16
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
#include <linux/io.h>

#include <linux/mfd/syscon.h>

#include <linux/module.h>

#include <linux/mutex.h>

#include <linux/of.h>

#include <linux/platform_device.h>

#include <linux/regmap.h>
@@ -19,6 +20,7 @@ 


struct fsi_master_aspeed {

	struct fsi_master	master;

	struct mutex		lock;	/* protect HW access */

	struct device		*dev;

	void __iomem		*base;

	struct clk		*clk;
@@ -254,6 +256,8 @@ static int aspeed_master_read(struct fsi_master *master, int link, 
	addr |= id << 21;

	addr += link * FSI_HUB_LINK_SIZE;



	mutex_lock(&aspeed->lock);



	switch (size) {

	case 1:

		ret = opb_readb(aspeed, fsi_base + addr, val);
@@ -265,14 +269,14 @@ static int aspeed_master_read(struct fsi_master *master, int link, 
		ret = opb_readl(aspeed, fsi_base + addr, val);

		break;

	default:

		return -EINVAL;

		ret = -EINVAL;

		goto done;

	}



	ret = check_errors(aspeed, ret);

	if (ret)

done:

	mutex_unlock(&aspeed->lock);

	return ret;



	return 0;

}



static int aspeed_master_write(struct fsi_master *master, int link,
@@ -287,6 +291,8 @@ static int aspeed_master_write(struct fsi_master *master, int link, 
	addr |= id << 21;

	addr += link * FSI_HUB_LINK_SIZE;



	mutex_lock(&aspeed->lock);



	switch (size) {

	case 1:

		ret = opb_writeb(aspeed, fsi_base + addr, *(u8 *)val);
@@ -298,14 +304,14 @@ static int aspeed_master_write(struct fsi_master *master, int link, 
		ret = opb_writel(aspeed, fsi_base + addr, *(__be32 *)val);

		break;

	default:

		return -EINVAL;

		ret = -EINVAL;

		goto done;

	}



	ret = check_errors(aspeed, ret);

	if (ret)

done:

	mutex_unlock(&aspeed->lock);

	return ret;



	return 0;

}



static int aspeed_master_link_enable(struct fsi_master *master, int link,
@@ -320,17 +326,21 @@ static int aspeed_master_link_enable(struct fsi_master *master, int link, 


	reg = cpu_to_be32(0x80000000 >> bit);



	if (!enable)

		return opb_writel(aspeed, ctrl_base + FSI_MCENP0 + (4 * idx),

				  reg);

	mutex_lock(&aspeed->lock);



	if (!enable) {

		ret = opb_writel(aspeed, ctrl_base + FSI_MCENP0 + (4 * idx), reg);

		goto done;

	}



	ret = opb_writel(aspeed, ctrl_base + FSI_MSENP0 + (4 * idx), reg);

	if (ret)

		return ret;

		goto done;



	mdelay(FSI_LINK_ENABLE_SETUP_TIME);



	return 0;

done:

	mutex_unlock(&aspeed->lock);

	return ret;

}



static int aspeed_master_term(struct fsi_master *master, int link, uint8_t id)
@@ -431,9 +441,11 @@ static ssize_t cfam_reset_store(struct device *dev, struct device_attribute *att 
{

	struct fsi_master_aspeed *aspeed = dev_get_drvdata(dev);



	mutex_lock(&aspeed->lock);

	gpiod_set_value(aspeed->cfam_reset_gpio, 1);

	usleep_range(900, 1000);

	gpiod_set_value(aspeed->cfam_reset_gpio, 0);

	mutex_unlock(&aspeed->lock);



	return count;

}
@@ -597,6 +609,7 @@ static int fsi_master_aspeed_probe(struct platform_device *pdev) 


	dev_set_drvdata(&pdev->dev, aspeed);



	mutex_init(&aspeed->lock);

	aspeed_master_init(aspeed);



	rc = fsi_master_register(&aspeed->master);

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