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authorRob Clark <robin.clark@oss.qualcomm.com>2025-06-29 05:54:49 +0300
committerRob Clark <robin.clark@oss.qualcomm.com>2025-06-29 05:54:49 +0300
commit74f1af95820fc2ee580a775a3a17c416db30b38c (patch)
tree7c82cffe3c1d99b99053d28b57a4ac5d81f85844 /drivers/misc/amd-sbi/rmi-i2c.c
parentd3deabe4c619875714b9a844b1a3d9752dbae1dd (diff)
parentf41830c57bb8e70e283b9db251c95f1270a8279d (diff)
downloadlinux-74f1af95820fc2ee580a775a3a17c416db30b38c.tar.xz
Merge remote-tracking branch 'drm/drm-next' into msm-next
Back-merge drm-next to (indirectly) get arm-smmu updates for making stall-on-fault more reliable. Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>
Diffstat (limited to 'drivers/misc/amd-sbi/rmi-i2c.c')
-rw-r--r--drivers/misc/amd-sbi/rmi-i2c.c133
1 files changed, 133 insertions, 0 deletions
diff --git a/drivers/misc/amd-sbi/rmi-i2c.c b/drivers/misc/amd-sbi/rmi-i2c.c
new file mode 100644
index 000000000000..f891f5af4bc6
--- /dev/null
+++ b/drivers/misc/amd-sbi/rmi-i2c.c
@@ -0,0 +1,133 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * rmi-i2c.c - Side band RMI over I2C support for AMD out
+ * of band management
+ *
+ * Copyright (C) 2024 Advanced Micro Devices, Inc.
+ */
+
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#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 sbrmi_data *data)
+{
+ int ctrl, ret;
+
+ /*
+ * Enable the SB-RMI Software alert status
+ * by writing 0 to bit 4 of Control register(0x1)
+ */
+ ret = regmap_read(data->regmap, SBRMI_CTRL, &ctrl);
+ if (ret < 0)
+ return ret;
+
+ if (ctrl & 0x10) {
+ ctrl &= ~0x10;
+ return regmap_write(data->regmap, SBRMI_CTRL, ctrl);
+ }
+
+ return 0;
+}
+
+static int sbrmi_get_max_pwr_limit(struct sbrmi_data *data)
+{
+ struct apml_mbox_msg msg = { 0 };
+ int ret;
+
+ msg.cmd = SBRMI_READ_PKG_MAX_PWR_LIMIT;
+ ret = rmi_mailbox_xfer(data, &msg);
+ if (ret < 0)
+ return ret;
+ data->pwr_limit_max = msg.mb_in_out;
+
+ return ret;
+}
+
+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;
+
+ 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(data);
+ if (ret < 0)
+ return ret;
+
+ /* Cache maximum power limit */
+ ret = sbrmi_get_max_pwr_limit(data);
+ if (ret < 0)
+ return ret;
+
+ data->dev_static_addr = client->addr;
+ dev_set_drvdata(dev, data);
+
+ ret = create_hwmon_sensor_device(dev, data);
+ if (ret < 0)
+ return ret;
+ return create_misc_rmi_device(data, dev);
+}
+
+static void sbrmi_i2c_remove(struct i2c_client *client)
+{
+ struct sbrmi_data *data = dev_get_drvdata(&client->dev);
+
+ misc_deregister(&data->sbrmi_misc_dev);
+ /* Assign fops and parent of misc dev to NULL */
+ data->sbrmi_misc_dev.fops = NULL;
+ data->sbrmi_misc_dev.parent = NULL;
+ dev_info(&client->dev, "Removed sbrmi-i2c driver\n");
+ return;
+}
+
+static const struct i2c_device_id sbrmi_id[] = {
+ {"sbrmi-i2c"},
+ {}
+};
+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 = {
+ .driver = {
+ .name = "sbrmi-i2c",
+ .of_match_table = of_match_ptr(sbrmi_of_match),
+ },
+ .probe = sbrmi_i2c_probe,
+ .remove = sbrmi_i2c_remove,
+ .id_table = sbrmi_id,
+};
+
+module_i2c_driver(sbrmi_driver);
+
+MODULE_AUTHOR("Akshay Gupta <akshay.gupta@amd.com>");
+MODULE_AUTHOR("Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>");
+MODULE_DESCRIPTION("Hwmon driver for AMD SB-RMI emulated sensor");
+MODULE_LICENSE("GPL");