Commit 3eb7754f authored by Ofir Bitton's avatar Ofir Bitton Committed by Oded Gabbay
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habanalabs: debugfs support for larger I2C transactions 



I2C debugfs support is limited to 1 byte. We extend functionality
to more than 1 byte by using one of the pad fields as a length.
No backward compatibility issues as new F/W versions will treat 0
length as a 1 byte length transaction.

Signed-off-by: default avatarOfir Bitton <obitton@habana.ai>
Reviewed-by: default avatarOded Gabbay <ogabbay@kernel.org>
Signed-off-by: default avatarOded Gabbay <ogabbay@kernel.org>
parent e617f5f4

Documentation/ABI/testing/debugfs-driver-habanalabs

+7 −0
Original line number Diff line number Diff line
@@ -155,6 +155,13 @@ Description: Triggers an I2C transaction that is generated by the device's 
                CPU. Writing to this file generates a write transaction while

                reading from the file generates a read transaction



What:           /sys/kernel/debug/habanalabs/hl<n>/i2c_len

Date:           Dec 2021

KernelVersion:  5.17

Contact:        obitton@habana.ai

Description:    Sets I2C length in bytes for I2C transaction that is generated by

                the device's CPU



What:           /sys/kernel/debug/habanalabs/hl<n>/i2c_reg

Date:           Jan 2019

KernelVersion:  5.1

drivers/misc/habanalabs/common/debugfs.c

+33 −17
Original line number Diff line number Diff line
@@ -15,19 +15,25 @@ 
#define MMU_ADDR_BUF_SIZE	40

#define MMU_ASID_BUF_SIZE	10

#define MMU_KBUF_SIZE		(MMU_ADDR_BUF_SIZE + MMU_ASID_BUF_SIZE)

#define I2C_MAX_TRANSACTION_LEN	8



static struct dentry *hl_debug_root;



static int hl_debugfs_i2c_read(struct hl_device *hdev, u8 i2c_bus, u8 i2c_addr,

				u8 i2c_reg, long *val)

				u8 i2c_reg, u8 i2c_len, u64 *val)

{

	struct cpucp_packet pkt;

	u64 result;

	int rc;



	if (!hl_device_operational(hdev, NULL))

		return -EBUSY;



	if (i2c_len > I2C_MAX_TRANSACTION_LEN) {

		dev_err(hdev->dev, "I2C transaction length %u, exceeds maximum of %u\n",

				i2c_len, I2C_MAX_TRANSACTION_LEN);

		return -EINVAL;

	}



	memset(&pkt, 0, sizeof(pkt));



	pkt.ctl = cpu_to_le32(CPUCP_PACKET_I2C_RD <<
@@ -35,12 +41,10 @@ static int hl_debugfs_i2c_read(struct hl_device *hdev, u8 i2c_bus, u8 i2c_addr, 
	pkt.i2c_bus = i2c_bus;

	pkt.i2c_addr = i2c_addr;

	pkt.i2c_reg = i2c_reg;

	pkt.i2c_len = i2c_len;



	rc = hdev->asic_funcs->send_cpu_message(hdev, (u32 *) &pkt, sizeof(pkt),

						0, &result);



	*val = (long) result;



						0, val);

	if (rc)

		dev_err(hdev->dev, "Failed to read from I2C, error %d\n", rc);
@@ -48,7 +52,7 @@ static int hl_debugfs_i2c_read(struct hl_device *hdev, u8 i2c_bus, u8 i2c_addr, 
}



static int hl_debugfs_i2c_write(struct hl_device *hdev, u8 i2c_bus, u8 i2c_addr,

				u8 i2c_reg, u32 val)

				u8 i2c_reg, u8 i2c_len, u64 val)

{

	struct cpucp_packet pkt;

	int rc;
@@ -56,6 +60,12 @@ static int hl_debugfs_i2c_write(struct hl_device *hdev, u8 i2c_bus, u8 i2c_addr, 
	if (!hl_device_operational(hdev, NULL))

		return -EBUSY;



	if (i2c_len > I2C_MAX_TRANSACTION_LEN) {

		dev_err(hdev->dev, "I2C transaction length %u, exceeds maximum of %u\n",

				i2c_len, I2C_MAX_TRANSACTION_LEN);

		return -EINVAL;

	}



	memset(&pkt, 0, sizeof(pkt));



	pkt.ctl = cpu_to_le32(CPUCP_PACKET_I2C_WR <<
@@ -63,6 +73,7 @@ static int hl_debugfs_i2c_write(struct hl_device *hdev, u8 i2c_bus, u8 i2c_addr, 
	pkt.i2c_bus = i2c_bus;

	pkt.i2c_addr = i2c_addr;

	pkt.i2c_reg = i2c_reg;

	pkt.i2c_len = i2c_len;

	pkt.value = cpu_to_le64(val);



	rc = hdev->asic_funcs->send_cpu_message(hdev, (u32 *) &pkt, sizeof(pkt),
@@ -899,22 +910,22 @@ static ssize_t hl_i2c_data_read(struct file *f, char __user *buf, 
	struct hl_dbg_device_entry *entry = file_inode(f)->i_private;

	struct hl_device *hdev = entry->hdev;

	char tmp_buf[32];

	long val;

	u64 val;

	ssize_t rc;



	if (*ppos)

		return 0;



	rc = hl_debugfs_i2c_read(hdev, entry->i2c_bus, entry->i2c_addr,

			entry->i2c_reg, &val);

			entry->i2c_reg, entry->i2c_len, &val);

	if (rc) {

		dev_err(hdev->dev,

			"Failed to read from I2C bus %d, addr %d, reg %d\n",

			entry->i2c_bus, entry->i2c_addr, entry->i2c_reg);

			"Failed to read from I2C bus %d, addr %d, reg %d, len %d\n",

			entry->i2c_bus, entry->i2c_addr, entry->i2c_reg, entry->i2c_len);

		return rc;

	}



	sprintf(tmp_buf, "0x%02lx\n", val);

	sprintf(tmp_buf, "%#02llx\n", val);

	rc = simple_read_from_buffer(buf, count, ppos, tmp_buf,

			strlen(tmp_buf));
@@ -926,19 +937,19 @@ static ssize_t hl_i2c_data_write(struct file *f, const char __user *buf, 
{

	struct hl_dbg_device_entry *entry = file_inode(f)->i_private;

	struct hl_device *hdev = entry->hdev;

	u32 value;

	u64 value;

	ssize_t rc;



	rc = kstrtouint_from_user(buf, count, 16, &value);

	rc = kstrtou64_from_user(buf, count, 16, &value);

	if (rc)

		return rc;



	rc = hl_debugfs_i2c_write(hdev, entry->i2c_bus, entry->i2c_addr,

			entry->i2c_reg, value);

			entry->i2c_reg, entry->i2c_len, value);

	if (rc) {

		dev_err(hdev->dev,

			"Failed to write 0x%02x to I2C bus %d, addr %d, reg %d\n",

			value, entry->i2c_bus, entry->i2c_addr, entry->i2c_reg);

			"Failed to write %#02llx to I2C bus %d, addr %d, reg %d, len %d\n",

			value, entry->i2c_bus, entry->i2c_addr, entry->i2c_reg, entry->i2c_len);

		return rc;

	}
@@ -1421,6 +1432,11 @@ void hl_debugfs_add_device(struct hl_device *hdev) 
				dev_entry->root,

				&dev_entry->i2c_reg);



	debugfs_create_u8("i2c_len",

				0644,

				dev_entry->root,

				&dev_entry->i2c_len);



	debugfs_create_file("i2c_data",

				0644,

				dev_entry->root,

drivers/misc/habanalabs/common/habanalabs.h

+2 −0
Original line number Diff line number Diff line
@@ -1889,6 +1889,7 @@ struct hl_debugfs_entry { 
 * @i2c_bus: generic u8 debugfs file for bus value to use in i2c_data_read.

 * @i2c_addr: generic u8 debugfs file for address value to use in i2c_data_read.

 * @i2c_reg: generic u8 debugfs file for register value to use in i2c_data_read.

 * @i2c_len: generic u8 debugfs file for length value to use in i2c_data_read.

 */

struct hl_dbg_device_entry {

	struct dentry			*root;
@@ -1917,6 +1918,7 @@ struct hl_dbg_device_entry { 
	u8				i2c_bus;

	u8				i2c_addr;

	u8				i2c_reg;

	u8				i2c_len;

};



/**

drivers/misc/habanalabs/include/common/cpucp_if.h

+8 −1
Original line number Diff line number Diff line
@@ -493,7 +493,14 @@ struct cpucp_packet { 
			__u8 i2c_bus;

			__u8 i2c_addr;

			__u8 i2c_reg;

			__u8 pad; /* unused */

			/*

			 * In legacy implemetations, i2c_len was not present,

			 * was unused and just added as pad.

			 * So if i2c_len is 0, it is treated as legacy

			 * and r/w 1 Byte, else if i2c_len is specified,

			 * its treated as new multibyte r/w support.

			 */

			__u8 i2c_len;

		};



		struct {/* For PLL info fetch */