firmware: samsung: acpm: Add TMU protocol support

The Thermal Management Unit (TMU) on the Google GS101 SoC is managed
through a hybrid model shared between the kernel and the Alive Clock
and Power Manager (ACPM) firmware.

Add the protocol helpers required to communicate with the ACPM for
thermal operations, including initialization, threshold configuration,
temperature reading, and system suspend/resume handshakes.

Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Reviewed-by: Peter Griffin <peter.griffin@linaro.org>
Link: https://patch.msgid.link/20260515-acpm-tmu-helpers-v2-5-8ca011d5a965@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

diff --git a/drivers/firmware/samsung/Makefile b/drivers/firmware/samsung/Makefile
index 80d4f89b33a9558b68c9083da675c70ec3d05f19..5a6f72bececfd98ba5af37d1d65fed48a3d8f912 100644 (file)
--- a/drivers/firmware/samsung/Makefile
+++ b/drivers/firmware/samsung/Makefile
@@ -3,4 +3,5 @@
 acpm-protocol-objs                     := exynos-acpm.o
 acpm-protocol-objs                     += exynos-acpm-pmic.o
 acpm-protocol-objs                     += exynos-acpm-dvfs.o
+acpm-protocol-objs                     += exynos-acpm-tmu.o
 obj-$(CONFIG_EXYNOS_ACPM_PROTOCOL)     += acpm-protocol.o

diff --git a/drivers/firmware/samsung/exynos-acpm-tmu.c b/drivers/firmware/samsung/exynos-acpm-tmu.c
new file mode 100644 (file)
index 0000000..c68d60b
--- /dev/null
+++ b/drivers/firmware/samsung/exynos-acpm-tmu.c
@@ -0,0 +1,239 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2020 Samsung Electronics Co., Ltd.
+ * Copyright 2020 Google LLC.
+ * Copyright 2026 Linaro Ltd.
+ */
+
+#include <linux/array_size.h>
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/firmware/samsung/exynos-acpm-protocol.h>
+#include <linux/ktime.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/units.h>
+
+#include "exynos-acpm.h"
+#include "exynos-acpm-tmu.h"
+
+/* IPC Request Types */
+#define ACPM_TMU_INIT          0x01
+#define ACPM_TMU_READ_TEMP     0x02
+#define ACPM_TMU_SUSPEND       0x04
+#define ACPM_TMU_RESUME                0x10
+#define ACPM_TMU_THRESHOLD     0x11
+#define ACPM_TMU_INTEN         0x12
+#define ACPM_TMU_CONTROL       0x13
+#define ACPM_TMU_IRQ_CLEAR     0x14
+
+#define ACPM_TMU_TX_DATA_LEN   8
+#define ACPM_TMU_RX_DATA_LEN   7
+
+struct acpm_tmu_tx {
+       u16 ctx;
+       u16 fw_use;
+       u8 type;
+       u8 rsvd0;
+       u8 tzid;
+       u8 rsvd1;
+       u8 data[ACPM_TMU_TX_DATA_LEN];
+} __packed;
+
+struct acpm_tmu_rx {
+       u16 ctx;
+       u16 fw_use;
+       u8 type;
+       s8 ret;
+       u8 tzid;
+       s8 temp;
+       u8 rsvd;
+       u8 data[ACPM_TMU_RX_DATA_LEN];
+} __packed;
+
+union acpm_tmu_msg {
+       u32 data[4];
+       struct acpm_tmu_tx tx;
+       struct acpm_tmu_rx rx;
+};
+
+static int acpm_tmu_to_linux_err(s8 fw_err)
+{
+       /*
+        * ACPM_TMU_INIT uses BIT(0) and BIT(1) of msg.rx.ret to flag APM
+        * capabilities. Treat zero and all positive values as success.
+        */
+       if (fw_err >= 0)
+               return 0;
+
+       if (fw_err == -1)
+               return -EACCES;
+
+       return -EIO;
+}
+
+int acpm_tmu_init(struct acpm_handle *handle, unsigned int acpm_chan_id)
+{
+       union acpm_tmu_msg msg = {0};
+       struct acpm_xfer xfer;
+       int ret;
+
+       msg.tx.type = ACPM_TMU_INIT;
+       acpm_set_xfer(&xfer, msg.data, ARRAY_SIZE(msg.data), acpm_chan_id,
+                     true);
+
+       ret = acpm_do_xfer(handle, &xfer);
+       if (ret)
+               return ret;
+
+       return acpm_tmu_to_linux_err(msg.rx.ret);
+}
+
+int acpm_tmu_read_temp(struct acpm_handle *handle, unsigned int acpm_chan_id,
+                      u8 tz, int *temp)
+{
+       union acpm_tmu_msg msg = {0};
+       struct acpm_xfer xfer;
+       int ret;
+
+       msg.tx.type = ACPM_TMU_READ_TEMP;
+       msg.tx.tzid = tz;
+
+       acpm_set_xfer(&xfer, msg.data, ARRAY_SIZE(msg.data), acpm_chan_id,
+                     true);
+
+       ret = acpm_do_xfer(handle, &xfer);
+       if (ret)
+               return ret;
+
+       ret = acpm_tmu_to_linux_err(msg.rx.ret);
+       if (ret)
+               return ret;
+
+       *temp = msg.rx.temp;
+
+       return 0;
+}
+
+int acpm_tmu_set_threshold(struct acpm_handle *handle,
+                          unsigned int acpm_chan_id, u8 tz,
+                          const u8 temperature[8], size_t tlen)
+{
+       union acpm_tmu_msg msg = {0};
+       struct acpm_xfer xfer;
+       int ret;
+
+       if (tlen > ACPM_TMU_TX_DATA_LEN)
+               return -EINVAL;
+
+       msg.tx.type = ACPM_TMU_THRESHOLD;
+       msg.tx.tzid = tz;
+       memcpy(msg.tx.data, temperature, tlen);
+
+       acpm_set_xfer(&xfer, msg.data, ARRAY_SIZE(msg.data), acpm_chan_id,
+                     true);
+
+       ret = acpm_do_xfer(handle, &xfer);
+       if (ret)
+               return ret;
+
+       return acpm_tmu_to_linux_err(msg.rx.ret);
+}
+
+int acpm_tmu_set_interrupt_enable(struct acpm_handle *handle,
+                                 unsigned int acpm_chan_id, u8 tz, u8 inten)
+{
+       union acpm_tmu_msg msg = {0};
+       struct acpm_xfer xfer;
+       int ret;
+
+       msg.tx.type = ACPM_TMU_INTEN;
+       msg.tx.tzid = tz;
+       msg.tx.data[0] = inten;
+
+       acpm_set_xfer(&xfer, msg.data, ARRAY_SIZE(msg.data), acpm_chan_id,
+                     true);
+
+       ret = acpm_do_xfer(handle, &xfer);
+       if (ret)
+               return ret;
+
+       return acpm_tmu_to_linux_err(msg.rx.ret);
+}
+
+int acpm_tmu_tz_control(struct acpm_handle *handle, unsigned int acpm_chan_id,
+                       u8 tz, bool enable)
+{
+       union acpm_tmu_msg msg = {0};
+       struct acpm_xfer xfer;
+       int ret;
+
+       msg.tx.type = ACPM_TMU_CONTROL;
+       msg.tx.tzid = tz;
+       msg.tx.data[0] = enable ? 1 : 0;
+
+       acpm_set_xfer(&xfer, msg.data, ARRAY_SIZE(msg.data), acpm_chan_id,
+                     true);
+
+       ret = acpm_do_xfer(handle, &xfer);
+       if (ret)
+               return ret;
+
+       return acpm_tmu_to_linux_err(msg.rx.ret);
+}
+
+int acpm_tmu_clear_tz_irq(struct acpm_handle *handle, unsigned int acpm_chan_id,
+                         u8 tz)
+{
+       union acpm_tmu_msg msg = {0};
+       struct acpm_xfer xfer;
+       int ret;
+
+       msg.tx.type = ACPM_TMU_IRQ_CLEAR;
+       msg.tx.tzid = tz;
+
+       acpm_set_xfer(&xfer, msg.data, ARRAY_SIZE(msg.data), acpm_chan_id,
+                     true);
+
+       ret = acpm_do_xfer(handle, &xfer);
+       if (ret)
+               return ret;
+
+       return acpm_tmu_to_linux_err(msg.rx.ret);
+}
+
+int acpm_tmu_suspend(struct acpm_handle *handle, unsigned int acpm_chan_id)
+{
+       union acpm_tmu_msg msg = {0};
+       struct acpm_xfer xfer;
+       int ret;
+
+       msg.tx.type = ACPM_TMU_SUSPEND;
+
+       acpm_set_xfer(&xfer, msg.data, ARRAY_SIZE(msg.data), acpm_chan_id,
+                     true);
+
+       ret = acpm_do_xfer(handle, &xfer);
+       if (ret)
+               return ret;
+
+       return acpm_tmu_to_linux_err(msg.rx.ret);
+}
+
+int acpm_tmu_resume(struct acpm_handle *handle, unsigned int acpm_chan_id)
+{
+       union acpm_tmu_msg msg = {0};
+       struct acpm_xfer xfer;
+       int ret;
+
+       msg.tx.type = ACPM_TMU_RESUME;
+
+       acpm_set_xfer(&xfer, msg.data, ARRAY_SIZE(msg.data), acpm_chan_id,
+                     true);
+
+       ret = acpm_do_xfer(handle, &xfer);
+       if (ret)
+               return ret;
+
+       return acpm_tmu_to_linux_err(msg.rx.ret);
+}

diff --git a/drivers/firmware/samsung/exynos-acpm-tmu.h b/drivers/firmware/samsung/exynos-acpm-tmu.h
new file mode 100644 (file)
index 0000000..8b89f29
--- /dev/null
+++ b/drivers/firmware/samsung/exynos-acpm-tmu.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright 2020 Samsung Electronics Co., Ltd.
+ * Copyright 2020 Google LLC.
+ * Copyright 2026 Linaro Ltd.
+ */
+#ifndef __EXYNOS_ACPM_TMU_H__
+#define __EXYNOS_ACPM_TMU_H__
+
+#include <linux/types.h>
+
+struct acpm_handle;
+
+int acpm_tmu_init(struct acpm_handle *handle, unsigned int acpm_chan_id);
+int acpm_tmu_read_temp(struct acpm_handle *handle, unsigned int acpm_chan_id,
+                      u8 tz, int *temp);
+int acpm_tmu_set_threshold(struct acpm_handle *handle,
+                          unsigned int acpm_chan_id, u8 tz,
+                          const u8 temperature[8], size_t tlen);
+int acpm_tmu_set_interrupt_enable(struct acpm_handle *handle,
+                                 unsigned int acpm_chan_id, u8 tz, u8 inten);
+int acpm_tmu_tz_control(struct acpm_handle *handle, unsigned int acpm_chan_id,
+                       u8 tz, bool enable);
+int acpm_tmu_clear_tz_irq(struct acpm_handle *handle, unsigned int acpm_chan_id,
+                         u8 tz);
+int acpm_tmu_suspend(struct acpm_handle *handle, unsigned int acpm_chan_id);
+int acpm_tmu_resume(struct acpm_handle *handle, unsigned int acpm_chan_id);
+#endif /* __EXYNOS_ACPM_TMU_H__ */

diff --git a/drivers/firmware/samsung/exynos-acpm.c b/drivers/firmware/samsung/exynos-acpm.c
index a1f73cc7cc8fa2d24284aafa2c0b1571df09a003..2f3b9a1bd74aa5ada98b5d3b12c630026ff8aeb3 100644 (file)
--- a/drivers/firmware/samsung/exynos-acpm.c
+++ b/drivers/firmware/samsung/exynos-acpm.c
@@ -32,6 +32,7 @@
 #include "exynos-acpm.h"
 #include "exynos-acpm-dvfs.h"
 #include "exynos-acpm-pmic.h"
+#include "exynos-acpm-tmu.h"
 
 #define ACPM_PROTOCOL_SEQNUM           GENMASK(21, 16)
 
@@ -684,6 +685,17 @@ static const struct acpm_ops exynos_acpm_driver_ops = {
                .bulk_write = acpm_pmic_bulk_write,
                .update_reg = acpm_pmic_update_reg,
        },
+
+       .tmu = {
+               .init = acpm_tmu_init,
+               .read_temp = acpm_tmu_read_temp,
+               .set_threshold = acpm_tmu_set_threshold,
+               .set_interrupt_enable = acpm_tmu_set_interrupt_enable,
+               .tz_control = acpm_tmu_tz_control,
+               .clear_tz_irq = acpm_tmu_clear_tz_irq,
+               .suspend = acpm_tmu_suspend,
+               .resume = acpm_tmu_resume,
+       },
 };
 
 static int acpm_probe(struct platform_device *pdev)

diff --git a/include/linux/firmware/samsung/exynos-acpm-protocol.h b/include/linux/firmware/samsung/exynos-acpm-protocol.h
index e13d9ac73ff6092ddbf81aed9fec76f2993c7512..8511c3c3983bf52ad5fb020253fae547ce117b91 100644 (file)
--- a/include/linux/firmware/samsung/exynos-acpm-protocol.h
+++ b/include/linux/firmware/samsung/exynos-acpm-protocol.h
@@ -34,9 +34,27 @@ struct acpm_pmic_ops {
                          u8 type, u8 reg, u8 chan, u8 value, u8 mask);
 };
 
+struct acpm_tmu_ops {
+       int (*init)(struct acpm_handle *handle, unsigned int acpm_chan_id);
+       int (*read_temp)(struct acpm_handle *handle, unsigned int acpm_chan_id,
+                        u8 tz, int *temp);
+       int (*set_threshold)(struct acpm_handle *handle,
+                            unsigned int acpm_chan_id, u8 tz,
+                            const u8 temperature[8], size_t tlen);
+       int (*set_interrupt_enable)(struct acpm_handle *handle,
+                                   unsigned int acpm_chan_id, u8 tz, u8 inten);
+       int (*tz_control)(struct acpm_handle *handle, unsigned int acpm_chan_id,
+                         u8 tz, bool enable);
+       int (*clear_tz_irq)(struct acpm_handle *handle,
+                           unsigned int acpm_chan_id, u8 tz);
+       int (*suspend)(struct acpm_handle *handle, unsigned int acpm_chan_id);
+       int (*resume)(struct acpm_handle *handle, unsigned int acpm_chan_id);
+};
+
 struct acpm_ops {
        struct acpm_dvfs_ops dvfs;
        struct acpm_pmic_ops pmic;
+       struct acpm_tmu_ops tmu;
 };
 
 /**