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authorEnrico Granata <egranata@chromium.org>2018-10-09 10:56:46 -0700
committerBenson Leung <bleung@chromium.org>2018-10-09 21:44:44 -0700
commitda1cf5a1cf124fc0a0b50c4ec78d5e97ee68bae2 (patch)
treedb6bdfa1b38fb5e9a4cb515050fd07a115d5534e
parent2c42dd6e0e3b0f5949924c8251a9d34ab373d2e0 (diff)
platform/chrome: Add a new interrupt path for cros_ec_lpc
This commit allows cros_ec_lpc to register a direct IRQ instead of relying on the ACPI notification chain to receive MKBP events. This change is done in the interest of allowing reduced jitter in the communication path between the CrOS EC and the host for receiving sensor data. Signed-off-by: Enrico Granata <egranata@chromium.org> Signed-off-by: Benson Leung <bleung@chromium.org>
-rw-r--r--drivers/platform/chrome/cros_ec_lpc.c15
1 files changed, 14 insertions, 1 deletions
diff --git a/drivers/platform/chrome/cros_ec_lpc.c b/drivers/platform/chrome/cros_ec_lpc.c
index 7ec8789bf161..e1b75775cd4a 100644
--- a/drivers/platform/chrome/cros_ec_lpc.c
+++ b/drivers/platform/chrome/cros_ec_lpc.c
@@ -25,6 +25,7 @@
#include <linux/dmi.h>
#include <linux/delay.h>
#include <linux/io.h>
+#include <linux/interrupt.h>
#include <linux/mfd/cros_ec.h>
#include <linux/mfd/cros_ec_commands.h>
#include <linux/module.h>
@@ -249,7 +250,7 @@ static int cros_ec_lpc_probe(struct platform_device *pdev)
acpi_status status;
struct cros_ec_device *ec_dev;
u8 buf[2];
- int ret;
+ int irq, ret;
if (!devm_request_region(dev, EC_LPC_ADDR_MEMMAP, EC_MEMMAP_SIZE,
dev_name(dev))) {
@@ -288,6 +289,18 @@ static int cros_ec_lpc_probe(struct platform_device *pdev)
sizeof(struct ec_response_get_protocol_info);
ec_dev->dout_size = sizeof(struct ec_host_request);
+ /*
+ * Some boards do not have an IRQ allotted for cros_ec_lpc,
+ * which makes ENXIO an expected (and safe) scenario.
+ */
+ irq = platform_get_irq(pdev, 0);
+ if (irq > 0)
+ ec_dev->irq = irq;
+ else if (irq != -ENXIO) {
+ dev_err(dev, "couldn't retrieve IRQ number (%d)\n", irq);
+ return irq;
+ }
+
ret = cros_ec_register(ec_dev);
if (ret) {
dev_err(dev, "couldn't register ec_dev (%d)\n", ret);