Commit 013f7e71 authored by Akshay Gupta's avatar Akshay Gupta Committed by Greg Kroah-Hartman
Browse files

misc: amd-sbi: Use regmap subsystem 



- regmap subsystem provides multiple benefits over direct smbus APIs
- subsystem adds another abstraction layer on top of struct i2c_client to
  make it easy to read or write registers.
- The subsystem can be helpful in following cases
  - Different types of bus (i2c/i3c), we have plans to support i3c.
  - Different Register address size (1byte/2byte)

Reviewed-by: default avatarNaveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Signed-off-by: default avatarAkshay Gupta <akshay.gupta@amd.com>
Link: https://lore.kernel.org/r/20250428063034.2145566-5-akshay.gupta@amd.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent f4dc6406

drivers/misc/amd-sbi/rmi-core.c

+12 −17
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
#include <linux/err.h>

#include <linux/i2c.h>

#include <linux/mutex.h>

#include <linux/regmap.h>

#include "rmi-core.h"



/* Mask for Status Register bit[1] */
@@ -21,6 +22,7 @@ 
int rmi_mailbox_xfer(struct sbrmi_data *data,

		     struct sbrmi_mailbox_msg *msg)

{

	unsigned int bytes;

	int i, ret, retry = 10;

	int sw_status;

	u8 byte;
@@ -28,14 +30,12 @@ int rmi_mailbox_xfer(struct sbrmi_data *data, 
	mutex_lock(&data->lock);



	/* Indicate firmware a command is to be serviced */

	ret = i2c_smbus_write_byte_data(data->client,

					SBRMI_INBNDMSG7, START_CMD);

	ret = regmap_write(data->regmap, SBRMI_INBNDMSG7, START_CMD);

	if (ret < 0)

		goto exit_unlock;



	/* Write the command to SBRMI::InBndMsg_inst0 */

	ret = i2c_smbus_write_byte_data(data->client,

					SBRMI_INBNDMSG0, msg->cmd);

	ret = regmap_write(data->regmap, SBRMI_INBNDMSG0, msg->cmd);

	if (ret < 0)

		goto exit_unlock;
@@ -46,8 +46,7 @@ int rmi_mailbox_xfer(struct sbrmi_data *data, 
	 */

	for (i = 0; i < 4; i++) {

		byte = (msg->data_in >> i * 8) & 0xff;

		ret = i2c_smbus_write_byte_data(data->client,

						SBRMI_INBNDMSG1 + i, byte);

		ret = regmap_write(data->regmap, SBRMI_INBNDMSG1 + i, byte);

		if (ret < 0)

			goto exit_unlock;

	}
@@ -56,8 +55,7 @@ int rmi_mailbox_xfer(struct sbrmi_data *data, 
	 * Write 0x01 to SBRMI::SoftwareInterrupt to notify firmware to

	 * perform the requested read or write command

	 */

	ret = i2c_smbus_write_byte_data(data->client,

					SBRMI_SW_INTERRUPT, TRIGGER_MAILBOX);

	ret = regmap_write(data->regmap, SBRMI_SW_INTERRUPT, TRIGGER_MAILBOX);

	if (ret < 0)

		goto exit_unlock;
@@ -67,8 +65,7 @@ int rmi_mailbox_xfer(struct sbrmi_data *data, 
	 * of the requested command

	 */

	do {

		sw_status = i2c_smbus_read_byte_data(data->client,

						     SBRMI_STATUS);

		ret = regmap_read(data->regmap, SBRMI_STATUS, &sw_status);

		if (sw_status < 0) {

			ret = sw_status;

			goto exit_unlock;
@@ -79,8 +76,6 @@ int rmi_mailbox_xfer(struct sbrmi_data *data, 
	} while (retry--);



	if (retry < 0) {

		dev_err(&data->client->dev,

			"Firmware fail to indicate command completion\n");

		ret = -EIO;

		goto exit_unlock;

	}
@@ -92,11 +87,11 @@ int rmi_mailbox_xfer(struct sbrmi_data *data, 
	 */

	if (msg->read) {

		for (i = 0; i < 4; i++) {

			ret = i2c_smbus_read_byte_data(data->client,

						       SBRMI_OUTBNDMSG1 + i);

			ret = regmap_read(data->regmap,

					  SBRMI_OUTBNDMSG1 + i, &bytes);

			if (ret < 0)

				goto exit_unlock;

			msg->data_out |= ret << i * 8;

			msg->data_out |= bytes << i * 8;

		}

	}
@@ -104,7 +99,7 @@ int rmi_mailbox_xfer(struct sbrmi_data *data, 
	 * BMC must write 1'b1 to SBRMI::Status[SwAlertSts] to clear the

	 * ALERT to initiator

	 */

	ret = i2c_smbus_write_byte_data(data->client, SBRMI_STATUS,

	ret = regmap_write(data->regmap, SBRMI_STATUS,

			   sw_status | SW_ALERT_MASK);



exit_unlock:

drivers/misc/amd-sbi/rmi-core.h

+2 −1
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
#include <linux/mutex.h>

#include <linux/i2c.h>

#include <linux/platform_device.h>

#include <linux/regmap.h>



/* SB-RMI registers */

enum sbrmi_reg {
@@ -47,7 +48,7 @@ enum sbrmi_msg_id { 


/* Each client has this additional data */

struct sbrmi_data {

	struct i2c_client *client;

	struct regmap *regmap;

	struct mutex lock;

	u32 pwr_limit_max;

};

drivers/misc/amd-sbi/rmi-i2c.c

+16 −9
Original line number Diff line number Diff line
@@ -13,24 +13,24 @@ 
#include <linux/module.h>

#include <linux/mutex.h>

#include <linux/of.h>

#include <linux/regmap.h>

#include "rmi-core.h"



static int sbrmi_enable_alert(struct i2c_client *client)

static int sbrmi_enable_alert(struct sbrmi_data *data)

{

	int ctrl;

	int ctrl, ret;



	/*

	 * Enable the SB-RMI Software alert status

	 * by writing 0 to bit 4 of Control register(0x1)

	 */

	ctrl = i2c_smbus_read_byte_data(client, SBRMI_CTRL);

	if (ctrl < 0)

		return ctrl;

	ret = regmap_read(data->regmap, SBRMI_CTRL, &ctrl);

	if (ret < 0)

		return ret;



	if (ctrl & 0x10) {

		ctrl &= ~0x10;

		return i2c_smbus_write_byte_data(client,

						 SBRMI_CTRL, ctrl);

		return regmap_write(data->regmap, SBRMI_CTRL, ctrl);

	}



	return 0;
@@ -55,17 +55,24 @@ static int sbrmi_i2c_probe(struct i2c_client *client) 
{

	struct device *dev = &client->dev;

	struct sbrmi_data *data;

	struct regmap_config sbrmi_i2c_regmap_config = {

		.reg_bits = 8,

		.val_bits = 8,

	};

	int ret;



	data = devm_kzalloc(dev, sizeof(struct sbrmi_data), GFP_KERNEL);

	if (!data)

		return -ENOMEM;



	data->client = client;

	mutex_init(&data->lock);



	data->regmap = devm_regmap_init_i2c(client, &sbrmi_i2c_regmap_config);

	if (IS_ERR(data->regmap))

		return PTR_ERR(data->regmap);



	/* Enable alert for SB-RMI sequence */

	ret = sbrmi_enable_alert(client);

	ret = sbrmi_enable_alert(data);

	if (ret < 0)

		return ret;