fsi: occ: Add support for P10

The P10 OCC has a different SRAM address for the command and response
buffers. In addition, the SBE commands to access the SRAM have changed
format. Add versioning to the driver to handle these differences.
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20201120010315.190737-3-joel@jms.id.auSigned-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/fsi/fsi-occ.c

@@ -14,6 +14,7 @@
 #include <linux/mutex.h>
 #include <linux/fsi-occ.h>
 #include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
@@ -24,8 +25,13 @@
 #define OCC_CMD_DATA_BYTES	4090
 #define OCC_RESP_DATA_BYTES	4089
 
-#define OCC_SRAM_CMD_ADDR	0xFFFBE000
-#define OCC_SRAM_RSP_ADDR	0xFFFBF000
+#define OCC_P9_SRAM_CMD_ADDR	0xFFFBE000
+#define OCC_P9_SRAM_RSP_ADDR	0xFFFBF000
+
+#define OCC_P10_SRAM_CMD_ADDR	0xFFFFD000
+#define OCC_P10_SRAM_RSP_ADDR	0xFFFFE000
+
+#define OCC_P10_SRAM_MODE	0x58	/* Normal mode, OCB channel 2 */
 
 /*
  * Assume we don't have much FFDC, if we do we'll overflow and
@@ -37,11 +43,14 @@
 #define OCC_TIMEOUT_MS		1000
 #define OCC_CMD_IN_PRG_WAIT_MS	50
 
+enum versions { occ_p9, occ_p10 };
+
 struct occ {
 	struct device *dev;
 	struct device *sbefifo;
 	char name[32];
 	int idx;
+	enum versions version;
 	struct miscdevice mdev;
 	struct mutex occ_lock;
 };
@@ -235,29 +244,43 @@ static int occ_verify_checksum(struct occ_response *resp, u16 data_length)
 	return 0;
 }
 
-static int occ_getsram(struct occ *occ, u32 address, void *data, ssize_t len)
+static int occ_getsram(struct occ *occ, u32 offset, void *data, ssize_t len)
 {
 	u32 data_len = ((len + 7) / 8) * 8;	/* must be multiples of 8 B */
-	size_t resp_len, resp_data_len;
-	__be32 *resp, cmd[5];
-	int rc;
+	size_t cmd_len, resp_len, resp_data_len;
+	__be32 *resp, cmd[6];
+	int idx = 0, rc;
 
 	/*
 	 * Magic sequence to do SBE getsram command. SBE will fetch data from
 	 * specified SRAM address.
 	 */
-	cmd[0] = cpu_to_be32(0x5);
+	switch (occ->version) {
+	default:
+	case occ_p9:
+		cmd_len = 5;
+		cmd[2] = cpu_to_be32(1);	/* Normal mode */
+		cmd[3] = cpu_to_be32(OCC_P9_SRAM_RSP_ADDR + offset);
+		break;
+	case occ_p10:
+		idx = 1;
+		cmd_len = 6;
+		cmd[2] = cpu_to_be32(OCC_P10_SRAM_MODE);
+		cmd[3] = 0;
+		cmd[4] = cpu_to_be32(OCC_P10_SRAM_RSP_ADDR + offset);
+		break;
+	}
+
+	cmd[0] = cpu_to_be32(cmd_len);
 	cmd[1] = cpu_to_be32(SBEFIFO_CMD_GET_OCC_SRAM);
-	cmd[2] = cpu_to_be32(1);
-	cmd[3] = cpu_to_be32(address);
-	cmd[4] = cpu_to_be32(data_len);
+	cmd[4 + idx] = cpu_to_be32(data_len);
 
 	resp_len = (data_len >> 2) + OCC_SBE_STATUS_WORDS;
 	resp = kzalloc(resp_len << 2, GFP_KERNEL);
 	if (!resp)
 		return -ENOMEM;
 
-	rc = sbefifo_submit(occ->sbefifo, cmd, 5, resp, &resp_len);
+	rc = sbefifo_submit(occ->sbefifo, cmd, cmd_len, resp, &resp_len);
 	if (rc)
 		goto free;
 
@@ -287,20 +310,21 @@ static int occ_getsram(struct occ *occ, u32 address, void *data, ssize_t len)
 	return rc;
 }
 
-static int occ_putsram(struct occ *occ, u32 address, const void *data,
-		       ssize_t len)
+static int occ_putsram(struct occ *occ, const void *data, ssize_t len)
 {
 	size_t cmd_len, buf_len, resp_len, resp_data_len;
 	u32 data_len = ((len + 7) / 8) * 8;	/* must be multiples of 8 B */
 	__be32 *buf;
-	int rc;
+	int idx = 0, rc;
+
+	cmd_len = (occ->version == occ_p10) ? 6 : 5;
 
 	/*
 	 * We use the same buffer for command and response, make
 	 * sure it's big enough
 	 */
 	resp_len = OCC_SBE_STATUS_WORDS;
-	cmd_len = (data_len >> 2) + 5;
+	cmd_len += data_len >> 2;
 	buf_len = max(cmd_len, resp_len);
 	buf = kzalloc(buf_len << 2, GFP_KERNEL);
 	if (!buf)
@@ -312,11 +336,23 @@ static int occ_putsram(struct occ *occ, u32 address, const void *data,
 	 */
 	buf[0] = cpu_to_be32(cmd_len);
 	buf[1] = cpu_to_be32(SBEFIFO_CMD_PUT_OCC_SRAM);
-	buf[2] = cpu_to_be32(1);
-	buf[3] = cpu_to_be32(address);
-	buf[4] = cpu_to_be32(data_len);
 
-	memcpy(&buf[5], data, len);
+	switch (occ->version) {
+	default:
+	case occ_p9:
+		buf[2] = cpu_to_be32(1);	/* Normal mode */
+		buf[3] = cpu_to_be32(OCC_P9_SRAM_CMD_ADDR);
+		break;
+	case occ_p10:
+		idx = 1;
+		buf[2] = cpu_to_be32(OCC_P10_SRAM_MODE);
+		buf[3] = 0;
+		buf[4] = cpu_to_be32(OCC_P10_SRAM_CMD_ADDR);
+		break;
+	}
+
+	buf[4 + idx] = cpu_to_be32(data_len);
+	memcpy(&buf[5 + idx], data, len);
 
 	rc = sbefifo_submit(occ->sbefifo, buf, cmd_len, buf, &resp_len);
 	if (rc)
@@ -356,21 +392,35 @@ static int occ_putsram(struct occ *occ, u32 address, const void *data,
 static int occ_trigger_attn(struct occ *occ)
 {
 	__be32 buf[OCC_SBE_STATUS_WORDS];
-	size_t resp_len, resp_data_len;
-	int rc;
+	size_t cmd_len, resp_len, resp_data_len;
+	int idx = 0, rc;
 
-	BUILD_BUG_ON(OCC_SBE_STATUS_WORDS < 7);
+	BUILD_BUG_ON(OCC_SBE_STATUS_WORDS < 8);
 	resp_len = OCC_SBE_STATUS_WORDS;
 
-	buf[0] = cpu_to_be32(0x5 + 0x2);        /* Chip-op length in words */
+	switch (occ->version) {
+	default:
+	case occ_p9:
+		cmd_len = 7;
+		buf[2] = cpu_to_be32(3); /* Circular mode */
+		buf[3] = 0;
+		break;
+	case occ_p10:
+		idx = 1;
+		cmd_len = 8;
+		buf[2] = cpu_to_be32(0xd0); /* Circular mode, OCB Channel 1 */
+		buf[3] = 0;
+		buf[4] = 0;
+		break;
+	}
+
+	buf[0] = cpu_to_be32(cmd_len);		/* Chip-op length in words */
 	buf[1] = cpu_to_be32(SBEFIFO_CMD_PUT_OCC_SRAM);
-	buf[2] = cpu_to_be32(0x3);              /* Mode: Circular */
-	buf[3] = cpu_to_be32(0x0);              /* Address: ignore in mode 3 */
-	buf[4] = cpu_to_be32(0x8);              /* Data length in bytes */
-	buf[5] = cpu_to_be32(0x20010000);       /* Trigger OCC attention */
-	buf[6] = 0;
+	buf[4 + idx] = cpu_to_be32(8);		/* Data length in bytes */
+	buf[5 + idx] = cpu_to_be32(0x20010000);	/* Trigger OCC attention */
+	buf[6 + idx] = 0;
 
-	rc = sbefifo_submit(occ->sbefifo, buf, 7, buf, &resp_len);
+	rc = sbefifo_submit(occ->sbefifo, buf, cmd_len, buf, &resp_len);
 	if (rc)
 		goto error;
 
@@ -429,7 +479,7 @@ int fsi_occ_submit(struct device *dev, const void *request, size_t req_len,
 
 	/* Extract the seq_no from the command (first byte) */
 	seq_no = *(const u8 *)request;
-	rc = occ_putsram(occ, OCC_SRAM_CMD_ADDR, request, req_len);
+	rc = occ_putsram(occ, request, req_len);
 	if (rc)
 		goto done;
 
@@ -440,7 +490,7 @@ int fsi_occ_submit(struct device *dev, const void *request, size_t req_len,
 	/* Read occ response header */
 	start = jiffies;
 	do {
-		rc = occ_getsram(occ, OCC_SRAM_RSP_ADDR, resp, 8);
+		rc = occ_getsram(occ, 0, resp, 8);
 		if (rc)
 			goto done;
 
@@ -476,8 +526,7 @@ int fsi_occ_submit(struct device *dev, const void *request, size_t req_len,
 	/* Grab the rest */
 	if (resp_data_length > 1) {
 		/* already got 3 bytes resp, also need 2 bytes checksum */
-		rc = occ_getsram(occ, OCC_SRAM_RSP_ADDR + 8,
-				 &resp->data[3], resp_data_length - 1);
+		rc = occ_getsram(occ, 8, &resp->data[3], resp_data_length - 1);
 		if (rc)
 			goto done;
 	}
@@ -517,6 +566,7 @@ static int occ_probe(struct platform_device *pdev)
 	if (!occ)
 		return -ENOMEM;
 
+	occ->version = (uintptr_t)of_device_get_match_data(dev);
 	occ->dev = dev;
 	occ->sbefifo = dev->parent;
 	mutex_init(&occ->occ_lock);
@@ -575,7 +625,14 @@ static int occ_remove(struct platform_device *pdev)
 }
 
 static const struct of_device_id occ_match[] = {
-	{ .compatible = "ibm,p9-occ" },
+	{
+		.compatible = "ibm,p9-occ",
+		.data = (void *)occ_p9
+	},
+	{
+		.compatible = "ibm,p10-occ",
+		.data = (void *)occ_p10
+	},
 	{ },
 };