commit 78aaf1d527115d534e3a00f2b55fff0f3f5f089a
author Daniel DeGrasse <daniel.degrasse@nxp.com> Fri Mar 08 12:22:00 2024 -0600
committer Henrik Brix Andersen <henrik@brixandersen.dk> Mon Mar 18 22:11:30 2024 +0100
tree 8343b6cb56405d5c14e6cadf872fb11829bdf445
parent b3e4eef8b53c1b1e585587a23dfb34751653cf8c

drivers: mipi_dbi: mipi_dbi_spi: do not take spinlock

Taking a spinlock will result in interrupts being blocked in the MIPI
DBI driver, which is not desired behavior while issuing SPI transfers,
since the driver may use interrupts to drive the transfer

Fixes #68815

Signed-off-by: Daniel DeGrasse <daniel.degrasse@nxp.com>
(cherry picked from commit 5b6fadc10d3be7120a808928f11389a6151944d2)

drivers/mipi_dbi/mipi_dbi_spi.c

diff --git a/drivers/mipi_dbi/mipi_dbi_spi.c b/drivers/mipi_dbi/mipi_dbi_spi.c
index 8745686..846158e 100644
--- a/drivers/mipi_dbi/mipi_dbi_spi.c
+++ b/drivers/mipi_dbi/mipi_dbi_spi.c
@@ -25,7 +25,7 @@
 struct mipi_dbi_spi_data {
 	/* Used for 3 wire mode */
 	uint16_t spi_byte;
-	struct k_spinlock lock;
+	struct k_mutex lock;
 };
 
 /* Expands to 1 if the node does not have the `write-only` property */
@@ -58,7 +58,11 @@
 		.count = 1,
 	};
 	int ret = 0;
-	k_spinlock_key_t spinlock_key = k_spin_lock(&data->lock);
+
+	ret = k_mutex_lock(&data->lock, K_FOREVER);
+	if (ret < 0) {
+		return ret;
+	}
 
 	if (dbi_config->mode == MIPI_DBI_MODE_SPI_3WIRE &&
 	    IS_ENABLED(CONFIG_MIPI_DBI_SPI_3WIRE)) {
@@ -124,7 +128,7 @@
 		ret = -ENOTSUP;
 	}
 out:
-	k_spin_unlock(&data->lock, spinlock_key);
+	k_mutex_unlock(&data->lock);
 	return ret;
 }
 
@@ -164,9 +168,12 @@
 		.count = 1,
 	};
 	int ret = 0;
-	k_spinlock_key_t spinlock_key = k_spin_lock(&data->lock);
 	struct spi_config tmp_config;
 
+	ret = k_mutex_lock(&data->lock, K_FOREVER);
+	if (ret < 0) {
+		return ret;
+	}
 	memcpy(&tmp_config, &dbi_config->config, sizeof(tmp_config));
 	if (dbi_config->mode == MIPI_DBI_MODE_SPI_3WIRE &&
 	    IS_ENABLED(CONFIG_MIPI_DBI_SPI_3WIRE)) {
@@ -231,7 +238,7 @@
 	}
 out:
 	spi_release(config->spi_dev, &tmp_config);
-	k_spin_unlock(&data->lock, spinlock_key);
+	k_mutex_unlock(&data->lock);
 	return ret;
 }
 
@@ -262,6 +269,7 @@
 static int mipi_dbi_spi_init(const struct device *dev)
 {
 	const struct mipi_dbi_spi_config *config = dev->config;
+	struct mipi_dbi_spi_data *data = dev->data;
 	int ret;
 
 	if (!device_is_ready(config->spi_dev)) {
@@ -291,6 +299,8 @@
 		}
 	}
 
+	k_mutex_init(&data->lock);
+
 	return 0;
 }