[PATCH v3 20/40] fsi: aspeed: Switch to spinlock

Eddie James
2024-05-16T18:19:50Z

In preparation for interrupt support, switch to a spinlock rather
than a mutex.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
---
drivers/fsi/fsi-master-aspeed.c | 25 ++++++++++++++-----------
1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/drivers/fsi/fsi-master-aspeed.c b/drivers/fsi/fsi-master-aspeed.c
index 10ca23cf58c2e..176e596b4391b 100644
--- a/drivers/fsi/fsi-master-aspeed.c
+++ b/drivers/fsi/fsi-master-aspeed.c
@@ -8,11 +8,11 @@
#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>
#include <linux/slab.h>
+#include <linux/spinlock.h>
#include <linux/iopoll.h>
#include <linux/gpio/consumer.h>

@@ -24,7 +24,7 @@ struct fsi_master_aspeed_data {

struct fsi_master_aspeed {
struct fsi_master master;
- struct mutex lock; /* protect HW access */
+ spinlock_t lock; /* protect HW access */
struct device *dev;
void __iomem *base;
void __iomem *ctrl;
@@ -251,6 +251,7 @@ static int aspeed_master_read(struct fsi_master *master, int link,
uint8_t id, uint32_t addr, void *val, size_t size)
{
struct fsi_master_aspeed *aspeed = to_fsi_master_aspeed(master);
+ unsigned long flags;
int ret;

if (id > 0x3)
@@ -259,7 +260,7 @@ static int aspeed_master_read(struct fsi_master *master, int link,
addr |= id << 21;
addr += link * FSI_HUB_LINK_SIZE;

- mutex_lock(&aspeed->lock);
+ spin_lock_irqsave(&aspeed->lock, flags);

switch (size) {
case 1:
@@ -278,7 +279,7 @@ static int aspeed_master_read(struct fsi_master *master, int link,

ret = check_errors(aspeed, ret);
done:
- mutex_unlock(&aspeed->lock);
+ spin_unlock_irqrestore(&aspeed->lock, flags);
return ret;
}

@@ -286,6 +287,7 @@ static int aspeed_master_write(struct fsi_master *master, int link,
uint8_t id, uint32_t addr, const void *val, size_t size)
{
struct fsi_master_aspeed *aspeed = to_fsi_master_aspeed(master);
+ unsigned long flags;
int ret;

if (id > 0x3)
@@ -294,7 +296,7 @@ static int aspeed_master_write(struct fsi_master *master, int link,
addr |= id << 21;
addr += link * FSI_HUB_LINK_SIZE;

- mutex_lock(&aspeed->lock);
+ spin_lock_irqsave(&aspeed->lock, flags);

switch (size) {
case 1:
@@ -313,7 +315,7 @@ static int aspeed_master_write(struct fsi_master *master, int link,

ret = check_errors(aspeed, ret);
done:
- mutex_unlock(&aspeed->lock);
+ spin_unlock_irqrestore(&aspeed->lock, flags);
return ret;
}

@@ -396,15 +398,16 @@ static ssize_t cfam_reset_store(struct device *dev, struct device_attribute *att
const char *buf, size_t count)
{
struct fsi_master_aspeed *aspeed = dev_get_drvdata(dev);
+ unsigned long flags;

trace_fsi_master_aspeed_cfam_reset(true);
- mutex_lock(&aspeed->lock);
+ spin_lock_irqsave(&aspeed->lock, flags);
gpiod_set_value(aspeed->cfam_reset_gpio, 1);
- usleep_range(900, 1000);
+ udelay(900);
gpiod_set_value(aspeed->cfam_reset_gpio, 0);
- usleep_range(900, 1000);
+ udelay(900);
regmap_write(aspeed->master.map, FSI_MRESP0, FSI_MRESP_RST_ALL_MASTER);
- mutex_unlock(&aspeed->lock);
+ spin_unlock_irqrestore(&aspeed->lock, flags);
trace_fsi_master_aspeed_cfam_reset(false);

return count;
@@ -498,6 +501,7 @@ static int fsi_master_aspeed_probe(struct platform_device *pdev)
return -ENOMEM;

aspeed->dev = &pdev->dev;
+ spin_lock_init(&aspeed->lock);

aspeed->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(aspeed->base)) {
@@ -583,7 +587,6 @@ static int fsi_master_aspeed_probe(struct platform_device *pdev)

dev_set_drvdata(&pdev->dev, aspeed);

- mutex_init(&aspeed->lock);
rc = fsi_master_init(&aspeed->master, clk_get_rate(aspeed->clk));
if (rc)
goto err_regmap;
--
2.39.3