Merge tag 'samsung-drivers-6.18' of https://git.kernel.org/pub/scm/linux/kernel/git/krzk/linux into soc/drivers

Samsung SoC drivers for v6.18

1. Google GS101:
   Enable CPU Idle, which needs programming C2 idle hints
   via ACPM firmware (Alive Clock and Power Manager).  The patch
   introducing this depends on 'local-timer-stop' Devicetree property,
   which was merged in v6.17.

   Fix handling error codes in ACPM firmware driver when talking to
   PMIC.

2. Exynos2200: Add dedicated compatible for serial engines (USI).

* tag 'samsung-drivers-6.18' of https://git.kernel.org/pub/scm/linux/kernel/git/krzk/linux:
  firmware: exynos-acpm: fix PMIC returned errno
  dt-bindings: soc: samsung: usi: add samsung,exynos2200-usi compatible
  soc: samsung: exynos-pmu: Enable CPU Idle for gs101

Link: https://lore.kernel.org/r/20250912135448.203678-2-krzysztof.kozlowski@linaro.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 20 insertions, 5 deletions

diff --git a/drivers/firmware/samsung/exynos-acpm-pmic.c b/drivers/firmware/samsung/exynos-acpm-pmic.c
index 39b33a356ebd..961d7599e422 100644
--- a/drivers/firmware/samsung/exynos-acpm-pmic.c
+++ b/drivers/firmware/samsung/exynos-acpm-pmic.c
@@ -4,7 +4,9 @@
  * Copyright 2020 Google LLC.
  * Copyright 2024 Linaro Ltd.
  */
+#include <linux/array_size.h>
 #include <linux/bitfield.h>
+#include <linux/errno.h>
 #include <linux/firmware/samsung/exynos-acpm-protocol.h>
 #include <linux/ktime.h>
 #include <linux/types.h>
@@ -33,6 +35,19 @@ enum exynos_acpm_pmic_func {
 	ACPM_PMIC_BULK_WRITE,
 };
 
+static const int acpm_pmic_linux_errmap[] = {
+	[0] = 0, /* ACPM_PMIC_SUCCESS */
+	[1] = -EACCES, /* Read register can't be accessed or issues to access it. */
+	[2] = -EACCES, /* Write register can't be accessed or issues to access it. */
+};
+
+static int acpm_pmic_to_linux_err(int err)
+{
+	if (err >= 0 && err < ARRAY_SIZE(acpm_pmic_linux_errmap))
+		return acpm_pmic_linux_errmap[err];
+	return -EIO;
+}
+
 static inline u32 acpm_pmic_set_bulk(u32 data, unsigned int i)
 {
 	return (data & ACPM_PMIC_BULK_MASK) << (ACPM_PMIC_BULK_SHIFT * i);
@@ -79,7 +94,7 @@ int acpm_pmic_read_reg(const struct acpm_handle *handle,
 
 	*buf = FIELD_GET(ACPM_PMIC_VALUE, xfer.rxd[1]);
 
-	return FIELD_GET(ACPM_PMIC_RETURN, xfer.rxd[1]);
+	return acpm_pmic_to_linux_err(FIELD_GET(ACPM_PMIC_RETURN, xfer.rxd[1]));
 }
 
 static void acpm_pmic_init_bulk_read_cmd(u32 cmd[4], u8 type, u8 reg, u8 chan,
@@ -110,7 +125,7 @@ int acpm_pmic_bulk_read(const struct acpm_handle *handle,
 	if (ret)
 		return ret;
 
-	ret = FIELD_GET(ACPM_PMIC_RETURN, xfer.rxd[1]);
+	ret = acpm_pmic_to_linux_err(FIELD_GET(ACPM_PMIC_RETURN, xfer.rxd[1]));
 	if (ret)
 		return ret;
 
@@ -150,7 +165,7 @@ int acpm_pmic_write_reg(const struct acpm_handle *handle,
 	if (ret)
 		return ret;
 
-	return FIELD_GET(ACPM_PMIC_RETURN, xfer.rxd[1]);
+	return acpm_pmic_to_linux_err(FIELD_GET(ACPM_PMIC_RETURN, xfer.rxd[1]));
 }
 
 static void acpm_pmic_init_bulk_write_cmd(u32 cmd[4], u8 type, u8 reg, u8 chan,
@@ -190,7 +205,7 @@ int acpm_pmic_bulk_write(const struct acpm_handle *handle,
 	if (ret)
 		return ret;
 
-	return FIELD_GET(ACPM_PMIC_RETURN, xfer.rxd[1]);
+	return acpm_pmic_to_linux_err(FIELD_GET(ACPM_PMIC_RETURN, xfer.rxd[1]));
 }
 
 static void acpm_pmic_init_update_cmd(u32 cmd[4], u8 type, u8 reg, u8 chan,
@@ -220,5 +235,5 @@ int acpm_pmic_update_reg(const struct acpm_handle *handle,
 	if (ret)
 		return ret;
 
-	return FIELD_GET(ACPM_PMIC_RETURN, xfer.rxd[1]);
+	return acpm_pmic_to_linux_err(FIELD_GET(ACPM_PMIC_RETURN, xfer.rxd[1]));
 }