* [PATCH 1/2] bindings: ipmi: Add alert GPIO enhancement for SSIF BMC driver
2024-10-19 15:38 [PATCH 0/2] ipmi: ssif_bmc: Add GPIO-based alert mechanism Potin Lai
@ 2024-10-19 15:38 ` Potin Lai
2024-10-19 16:22 ` Rob Herring (Arm)
2024-10-19 15:38 ` [PATCH 2/2] ipmi: ssif_bmc: add GPIO-based alert mechanism Potin Lai
1 sibling, 1 reply; 4+ messages in thread
From: Potin Lai @ 2024-10-19 15:38 UTC (permalink / raw)
To: Corey Minyard, Rob Herring, Krzysztof Kozlowski, Conor Dooley,
Quan Nguyen, Patrick Williams
Cc: openipmi-developer, devicetree, linux-kernel, Cosmo Chou,
Potin Lai, Potin Lai
Introduce the `alert-gpios` property to define an alert pin, enabling
the BMC to notify the host when a response is available.
Signed-off-by: Potin Lai <potin.lai.pt@gmail.com>
---
Documentation/devicetree/bindings/ipmi/ssif-bmc.yaml | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/Documentation/devicetree/bindings/ipmi/ssif-bmc.yaml b/Documentation/devicetree/bindings/ipmi/ssif-bmc.yaml
index 02b662d780bb..104283fa851a 100644
--- a/Documentation/devicetree/bindings/ipmi/ssif-bmc.yaml
+++ b/Documentation/devicetree/bindings/ipmi/ssif-bmc.yaml
@@ -19,6 +19,12 @@ properties:
reg:
maxItems: 1
+ alert-gpios:
+ description:
+ GPIO pin designated for SSIF alert, used by the BMC to notify the
+ host when a response is available.
+ maxItems: 1
+
required:
- compatible
- reg
@@ -34,5 +40,6 @@ examples:
ssif-bmc@10 {
compatible = "ssif-bmc";
reg = <0x10>;
+ alert-gpios = <&gpio 0 GPIO_ACTIVE_LOW>;
};
};
--
2.31.1
^ permalink raw reply [flat|nested] 4+ messages in thread* [PATCH 2/2] ipmi: ssif_bmc: add GPIO-based alert mechanism
2024-10-19 15:38 [PATCH 0/2] ipmi: ssif_bmc: Add GPIO-based alert mechanism Potin Lai
2024-10-19 15:38 ` [PATCH 1/2] bindings: ipmi: Add alert GPIO enhancement for SSIF BMC driver Potin Lai
@ 2024-10-19 15:38 ` Potin Lai
1 sibling, 0 replies; 4+ messages in thread
From: Potin Lai @ 2024-10-19 15:38 UTC (permalink / raw)
To: Corey Minyard, Rob Herring, Krzysztof Kozlowski, Conor Dooley,
Quan Nguyen, Patrick Williams
Cc: openipmi-developer, devicetree, linux-kernel, Cosmo Chou,
Potin Lai, Potin Lai, Cosmo Chou
From: Cosmo Chou <chou.cosmo@gmail.com>
Implement GPIO-based alert mechanism in the SSIF BMC driver to notify
the host when a response is ready.
This improves host-BMC communication efficiency by providing immediate
notification, potentially reducing host polling overhead.
Signed-off-by: Cosmo Chou <chou.cosmo@gmail.com>
---
drivers/char/ipmi/ssif_bmc.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/drivers/char/ipmi/ssif_bmc.c b/drivers/char/ipmi/ssif_bmc.c
index a14fafc583d4..73be166b0042 100644
--- a/drivers/char/ipmi/ssif_bmc.c
+++ b/drivers/char/ipmi/ssif_bmc.c
@@ -17,6 +17,7 @@
#include <linux/spinlock.h>
#include <linux/timer.h>
#include <linux/jiffies.h>
+#include <linux/gpio/consumer.h>
#include <linux/ipmi_ssif_bmc.h>
#define DEVICE_NAME "ipmi-ssif-host"
@@ -102,6 +103,7 @@ struct ssif_bmc_ctx {
struct ssif_part_buffer part_buf;
struct ipmi_ssif_msg response;
struct ipmi_ssif_msg request;
+ struct gpio_desc *alert;
};
static inline struct ssif_bmc_ctx *to_ssif_bmc(struct file *file)
@@ -222,6 +224,9 @@ static ssize_t ssif_bmc_write(struct file *file, const char __user *buf, size_t
/* Clean old request buffer */
memset(&ssif_bmc->request, 0, sizeof(struct ipmi_ssif_msg));
+
+ if (!IS_ERR(ssif_bmc->alert))
+ gpiod_set_value(ssif_bmc->alert, 1);
exit:
spin_unlock_irqrestore(&ssif_bmc->lock, flags);
@@ -584,6 +589,9 @@ static void process_smbus_cmd(struct ssif_bmc_ctx *ssif_bmc, u8 *val)
memset(&ssif_bmc->part_buf.payload[0], 0, MAX_PAYLOAD_PER_TRANSACTION);
if (*val == SSIF_IPMI_SINGLEPART_WRITE || *val == SSIF_IPMI_MULTIPART_WRITE_START) {
+ if (!IS_ERR(ssif_bmc->alert))
+ gpiod_set_value(ssif_bmc->alert, 0);
+
/*
* The response maybe not come in-time, causing host SSIF driver
* to timeout and resend a new request. In such case check for
@@ -640,6 +648,8 @@ static void on_read_requested_event(struct ssif_bmc_ctx *ssif_bmc, u8 *val)
calculate_response_part_pec(&ssif_bmc->part_buf);
ssif_bmc->part_buf.index = 0;
*val = ssif_bmc->part_buf.length;
+ if (!IS_ERR(ssif_bmc->alert))
+ gpiod_set_value(ssif_bmc->alert, 0);
}
static void on_read_processed_event(struct ssif_bmc_ctx *ssif_bmc, u8 *val)
@@ -808,6 +818,11 @@ static int ssif_bmc_probe(struct i2c_client *client)
if (!ssif_bmc)
return -ENOMEM;
+ /* Request GPIO for alerting the host that response is ready */
+ ssif_bmc->alert = devm_gpiod_get(&client->dev, "alert", GPIOD_ASIS);
+ if (!IS_ERR(ssif_bmc->alert))
+ gpiod_direction_output(ssif_bmc->alert, 0);
+
spin_lock_init(&ssif_bmc->lock);
init_waitqueue_head(&ssif_bmc->wait_queue);
--
2.31.1
^ permalink raw reply [flat|nested] 4+ messages in thread