[PATCH 4/4] ipmi: bt-bmc: Read LPC address and SerIRQ from device tree

[Yu-Che Hsieh via B4 Relay]

From: Yu-Che Hsieh <yc_hsieh@xxxxxxxxxxxxxx>

The BT interface currently programs a fixed host LPC IO address and

SerIRQ number. This works for the existing single-channel setup, but

does not allow the host interface parameters to be described by firmware.

Read the LPC IO address from aspeed,lpc-io-reg and the SerIRQ number

and interrupt type from aspeed,lpc-interrupts. Keep the existing IO

address, SerIRQ number, and level-low interrupt type as defaults when

the properties are not present.

Signed-off-by: Yu-Che Hsieh <yc_hsieh@xxxxxxxxxxxxxx>
---
 drivers/char/ipmi/bt-bmc.c | 39 +++++++++++++++++++++++++++++++++++++--
 1 file changed, 37 insertions(+), 2 deletions(-)

diff --git a/drivers/char/ipmi/bt-bmc.c b/drivers/char/ipmi/bt-bmc.c
index 486ecc0b6815..6e1f941e63db 100644
--- a/drivers/char/ipmi/bt-bmc.c
+++ b/drivers/char/ipmi/bt-bmc.c
@@ -65,6 +65,12 @@ struct bt_bmc {
 	struct timer_list	poll_timer;
 	struct mutex		mutex;
 	atomic_t		open_count;
+	u32			io_addr;
+
+	struct {
+		u32 id;
+		u32 type;
+	} sirq;
 };
 
 static u8 bt_inb(struct bt_bmc *bt_bmc, int reg)
@@ -429,6 +435,33 @@ static int bt_bmc_probe(struct platform_device *pdev)
 	mutex_init(&bt_bmc->mutex);
 	init_waitqueue_head(&bt_bmc->queue);
 
+	rc = of_property_read_u32(dev->of_node, "aspeed,lpc-io-reg",
+				  &bt_bmc->io_addr);
+	if (rc) {
+		bt_bmc->io_addr = BT_IO_BASE;
+	} else if (bt_bmc->io_addr > FIELD_MAX(BT_CR0_IO_BASE)) {
+		dev_err(dev, "invalid LPC IO address\n");
+		return -EINVAL;
+	}
+
+	rc = of_property_read_u32_array(dev->of_node, "aspeed,lpc-interrupts",
+					(u32 *)&bt_bmc->sirq, 2);
+	if (rc) {
+		bt_bmc->sirq.id = BT_IRQ;
+		bt_bmc->sirq.type = IRQ_TYPE_LEVEL_LOW;
+	} else {
+		if (bt_bmc->sirq.id > FIELD_MAX(BT_CR0_SIRQ)) {
+			dev_err(dev, "invalid SerIRQ number\n");
+			return -EINVAL;
+		}
+
+		if (bt_bmc->sirq.type != IRQ_TYPE_LEVEL_HIGH &&
+		    bt_bmc->sirq.type != IRQ_TYPE_LEVEL_LOW) {
+			dev_err(dev, "invalid SerIRQ type\n");
+			return -EINVAL;
+		}
+	}
+
 	bt_bmc->miscdev.minor	= MISC_DYNAMIC_MINOR;
 	bt_bmc->miscdev.name	= DEVICE_NAME;
 	bt_bmc->miscdev.fops	= &bt_bmc_fops;
@@ -450,8 +483,10 @@ static int bt_bmc_probe(struct platform_device *pdev)
 		add_timer(&bt_bmc->poll_timer);
 	}
 
-	writel(FIELD_PREP(BT_CR0_IO_BASE, BT_IO_BASE) |
-	       FIELD_PREP(BT_CR0_SIRQ, BT_IRQ) |
+	writel(FIELD_PREP(BT_CR0_IO_BASE, bt_bmc->io_addr) |
+	       FIELD_PREP(BT_CR0_SIRQ, bt_bmc->sirq.id) |
+	       FIELD_PREP(BT_CR0_SIRQ_TYPE,
+			  bt_bmc->sirq.type == IRQ_TYPE_LEVEL_LOW ? 0 : 1) |
 	       BT_CR0_EN_CLR_SLV_RDP |
 	       BT_CR0_EN_CLR_SLV_WRP |
 	       BT_CR0_ENABLE_IBT,

-- 
2.34.1