Author | Tokens | Token Proportion | Commits | Commit Proportion |
---|---|---|---|---|
Akshay Gupta | 1208 | 99.83% | 1 | 33.33% |
Uwe Kleine-König | 1 | 0.08% | 1 | 33.33% |
Krzysztof Kozlowski | 1 | 0.08% | 1 | 33.33% |
Total | 1210 | 3 |
// SPDX-License-Identifier: GPL-2.0-or-later /* * sbrmi.c - hwmon driver for a SB-RMI mailbox * compliant AMD SoC device. * * Copyright (C) 2020-2021 Advanced Micro Devices, Inc. */ #include <linux/delay.h> #include <linux/err.h> #include <linux/hwmon.h> #include <linux/i2c.h> #include <linux/init.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/of.h> /* Do not allow setting negative power limit */ #define SBRMI_PWR_MIN 0 /* Mask for Status Register bit[1] */ #define SW_ALERT_MASK 0x2 /* Software Interrupt for triggering */ #define START_CMD 0x80 #define TRIGGER_MAILBOX 0x01 /* * SB-RMI supports soft mailbox service request to MP1 (power management * firmware) through SBRMI inbound/outbound message registers. * SB-RMI message IDs */ enum sbrmi_msg_id { SBRMI_READ_PKG_PWR_CONSUMPTION = 0x1, SBRMI_WRITE_PKG_PWR_LIMIT, SBRMI_READ_PKG_PWR_LIMIT, SBRMI_READ_PKG_MAX_PWR_LIMIT, }; /* SB-RMI registers */ enum sbrmi_reg { SBRMI_CTRL = 0x01, SBRMI_STATUS, SBRMI_OUTBNDMSG0 = 0x30, SBRMI_OUTBNDMSG1, SBRMI_OUTBNDMSG2, SBRMI_OUTBNDMSG3, SBRMI_OUTBNDMSG4, SBRMI_OUTBNDMSG5, SBRMI_OUTBNDMSG6, SBRMI_OUTBNDMSG7, SBRMI_INBNDMSG0, SBRMI_INBNDMSG1, SBRMI_INBNDMSG2, SBRMI_INBNDMSG3, SBRMI_INBNDMSG4, SBRMI_INBNDMSG5, SBRMI_INBNDMSG6, SBRMI_INBNDMSG7, SBRMI_SW_INTERRUPT, }; /* Each client has this additional data */ struct sbrmi_data { struct i2c_client *client; struct mutex lock; u32 pwr_limit_max; }; struct sbrmi_mailbox_msg { u8 cmd; bool read; u32 data_in; u32 data_out; }; static int sbrmi_enable_alert(struct i2c_client *client) { int ctrl; /* * 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; if (ctrl & 0x10) { ctrl &= ~0x10; return i2c_smbus_write_byte_data(client, SBRMI_CTRL, ctrl); } return 0; } static int rmi_mailbox_xfer(struct sbrmi_data *data, struct sbrmi_mailbox_msg *msg) { int i, ret, retry = 10; int sw_status; u8 byte; mutex_lock(&data->lock); /* Indicate firmware a command is to be serviced */ ret = i2c_smbus_write_byte_data(data->client, 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); if (ret < 0) goto exit_unlock; /* * For both read and write the initiator (BMC) writes * Command Data In[31:0] to SBRMI::InBndMsg_inst[4:1] * SBRMI_x3C(MSB):SBRMI_x39(LSB) */ 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); if (ret < 0) goto exit_unlock; } /* * 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); if (ret < 0) goto exit_unlock; /* * Firmware will write SBRMI::Status[SwAlertSts]=1 to generate * an ALERT (if enabled) to initiator (BMC) to indicate completion * of the requested command */ do { sw_status = i2c_smbus_read_byte_data(data->client, SBRMI_STATUS); if (sw_status < 0) { ret = sw_status; goto exit_unlock; } if (sw_status & SW_ALERT_MASK) break; usleep_range(50, 100); } while (retry--); if (retry < 0) { dev_err(&data->client->dev, "Firmware fail to indicate command completion\n"); ret = -EIO; goto exit_unlock; } /* * For a read operation, the initiator (BMC) reads the firmware * response Command Data Out[31:0] from SBRMI::OutBndMsg_inst[4:1] * {SBRMI_x34(MSB):SBRMI_x31(LSB)}. */ if (msg->read) { for (i = 0; i < 4; i++) { ret = i2c_smbus_read_byte_data(data->client, SBRMI_OUTBNDMSG1 + i); if (ret < 0) goto exit_unlock; msg->data_out |= ret << i * 8; } } /* * 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, sw_status | SW_ALERT_MASK); exit_unlock: mutex_unlock(&data->lock); return ret; } static int sbrmi_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long *val) { struct sbrmi_data *data = dev_get_drvdata(dev); struct sbrmi_mailbox_msg msg = { 0 }; int ret; if (type != hwmon_power) return -EINVAL; msg.read = true; switch (attr) { case hwmon_power_input: msg.cmd = SBRMI_READ_PKG_PWR_CONSUMPTION; ret = rmi_mailbox_xfer(data, &msg); break; case hwmon_power_cap: msg.cmd = SBRMI_READ_PKG_PWR_LIMIT; ret = rmi_mailbox_xfer(data, &msg); break; case hwmon_power_cap_max: msg.data_out = data->pwr_limit_max; ret = 0; break; default: return -EINVAL; } if (ret < 0) return ret; /* hwmon power attributes are in microWatt */ *val = (long)msg.data_out * 1000; return ret; } static int sbrmi_write(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long val) { struct sbrmi_data *data = dev_get_drvdata(dev); struct sbrmi_mailbox_msg msg = { 0 }; if (type != hwmon_power && attr != hwmon_power_cap) return -EINVAL; /* * hwmon power attributes are in microWatt * mailbox read/write is in mWatt */ val /= 1000; val = clamp_val(val, SBRMI_PWR_MIN, data->pwr_limit_max); msg.cmd = SBRMI_WRITE_PKG_PWR_LIMIT; msg.data_in = val; msg.read = false; return rmi_mailbox_xfer(data, &msg); } static umode_t sbrmi_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr, int channel) { switch (type) { case hwmon_power: switch (attr) { case hwmon_power_input: case hwmon_power_cap_max: return 0444; case hwmon_power_cap: return 0644; } break; default: break; } return 0; } static const struct hwmon_channel_info * const sbrmi_info[] = { HWMON_CHANNEL_INFO(power, HWMON_P_INPUT | HWMON_P_CAP | HWMON_P_CAP_MAX), NULL }; static const struct hwmon_ops sbrmi_hwmon_ops = { .is_visible = sbrmi_is_visible, .read = sbrmi_read, .write = sbrmi_write, }; static const struct hwmon_chip_info sbrmi_chip_info = { .ops = &sbrmi_hwmon_ops, .info = sbrmi_info, }; static int sbrmi_get_max_pwr_limit(struct sbrmi_data *data) { struct sbrmi_mailbox_msg msg = { 0 }; int ret; msg.cmd = SBRMI_READ_PKG_MAX_PWR_LIMIT; msg.read = true; ret = rmi_mailbox_xfer(data, &msg); if (ret < 0) return ret; data->pwr_limit_max = msg.data_out; return ret; } static int sbrmi_probe(struct i2c_client *client) { struct device *dev = &client->dev; struct device *hwmon_dev; struct sbrmi_data *data; int ret; data = devm_kzalloc(dev, sizeof(struct sbrmi_data), GFP_KERNEL); if (!data) return -ENOMEM; data->client = client; mutex_init(&data->lock); /* Enable alert for SB-RMI sequence */ ret = sbrmi_enable_alert(client); if (ret < 0) return ret; /* Cache maximum power limit */ ret = sbrmi_get_max_pwr_limit(data); if (ret < 0) return ret; hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, data, &sbrmi_chip_info, NULL); return PTR_ERR_OR_ZERO(hwmon_dev); } static const struct i2c_device_id sbrmi_id[] = { {"sbrmi", 0}, {} }; MODULE_DEVICE_TABLE(i2c, sbrmi_id); static const struct of_device_id __maybe_unused sbrmi_of_match[] = { { .compatible = "amd,sbrmi", }, { }, }; MODULE_DEVICE_TABLE(of, sbrmi_of_match); static struct i2c_driver sbrmi_driver = { .class = I2C_CLASS_HWMON, .driver = { .name = "sbrmi", .of_match_table = of_match_ptr(sbrmi_of_match), }, .probe = sbrmi_probe, .id_table = sbrmi_id, }; module_i2c_driver(sbrmi_driver); MODULE_AUTHOR("Akshay Gupta <akshay.gupta@amd.com>"); MODULE_DESCRIPTION("Hwmon driver for AMD SB-RMI emulated sensor"); MODULE_LICENSE("GPL");
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