i2c: busses: i2c-bcm2835: limits cdiv to allowed values (a294aba1) · Commits · e / devices / android_kernel_oneplus_sm8150

Checks if the cdiv value is in between min (0x2) and max (0xFFFE) supported values by the bcm2835. If not, it returns -ENODEV. See page 33/34 of BCM2835-ARM-Peripherals.pdf for the DIV register. https://www.raspberrypi.org/wp-content/uploads/2012/02/BCM2835-ARM-Peripherals.pdf Signed-off-by:

Silvan Wicki <linux_wi@tinag.ch> [wsa: resolved a merge conflict] Signed-off-by:

drivers/i2c/busses/i2c-bcm2835.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -52,6 +52,9 @@

		#define BCM2835_I2C_BITMSK_S 0x03FF

		#define BCM2835_I2C_CDIV_MIN 0x0002
		#define BCM2835_I2C_CDIV_MAX 0xFFFE

		#define BCM2835_I2C_TIMEOUT (msecs_to_jiffies(1000))

		struct bcm2835_i2c_dev {
		@@ -261,6 +264,11 @@ static int bcm2835_i2c_probe(struct platform_device *pdev)
		*/
		if (divider & 1)
		divider++;
		if ((divider < BCM2835_I2C_CDIV_MIN) \|\|
		(divider > BCM2835_I2C_CDIV_MAX)) {
		dev_err(&pdev->dev, "Invalid clock-frequency\n");
		return -ENODEV;
		}
		bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_DIV, divider);

		irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);