[PATCH v3 5/6] spmi: apple: lock around FIFOs

From: Alba Mendez <[email protected]>

The driver was missing locking around register interactions

Signed-off-by: Alba Mendez <[email protected]>
Signed-off-by: Sasha Finkelstein <[email protected]>
---
 drivers/spmi/spmi-apple-controller.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/spmi/spmi-apple-controller.c b/drivers/spmi/spmi-apple-controller.c
index 8c9a70ba0422..74d4b5d98b11 100644
--- a/drivers/spmi/spmi-apple-controller.c
+++ b/drivers/spmi/spmi-apple-controller.c
@@ -14,6 +14,7 @@
 #include <linux/io.h>
 #include <linux/iopoll.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/platform_device.h>
 #include <linux/spmi.h>
 
@@ -35,6 +36,7 @@
 
 struct apple_spmi {
 	void __iomem *regs;
+	struct mutex fifo_lock;
 };
 
 #define poll_reg(spmi, reg, val, cond) \
@@ -87,6 +89,8 @@ static int spmi_raw_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid,
 	size_t i = 0, j;
 	int ret;
 
+	guard(mutex)(&spmi->fifo_lock);
+
 	writel(spmi_cmd, spmi->regs + SPMI_CMD_REG);
 
 	while (i < len) {
@@ -193,6 +197,7 @@ static int apple_spmi_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	spmi = spmi_controller_get_drvdata(ctrl);
+	mutex_init(&spmi->fifo_lock);
 
 	spmi->regs = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(spmi->regs))

-- 
2.55.0