[devel] [PATCH 06/35] hwmon: bt1-pvt: define pvt_readl/pvt_writel for Baikal-M SoC

[asheplyakov на yandex.ru]

From: Alexey Sheplyakov <asheplyakov на basealt.ru>

On Baikal-M Linux has to call into firmware (ARM-TF) to access
PVT registers.

Signed-off-by: Alexey Sheplyakov <asheplyakov на basealt.ru>
X-feature-Baikal-M
---
 drivers/hwmon/bt1-pvt.c | 23 +++++++++++++++++++++++
 drivers/hwmon/bt1-pvt.h |  8 ++++++++
 2 files changed, 31 insertions(+)

diff --git a/drivers/hwmon/bt1-pvt.c b/drivers/hwmon/bt1-pvt.c
index c05fe8df0839..2f2a222bd136 100644
--- a/drivers/hwmon/bt1-pvt.c
+++ b/drivers/hwmon/bt1-pvt.c
@@ -29,6 +29,9 @@
 #include <linux/seqlock.h>
 #include <linux/sysfs.h>
 #include <linux/types.h>
+#ifdef CONFIG_ARM64
+#include <linux/arm-smccc.h>
+#endif
 
 #include "bt1-pvt.h"
 
@@ -138,6 +141,7 @@ static long pvt_calc_poly(const struct pvt_poly *poly, long data)
 	return ret / poly->total_divider;
 }
 
+#ifdef BT1_PVT_DIRECT_REG_ACCESS
 static inline u32 pvt_readl(struct pvt_hwmon const *pvt, int reg) {
 	return readl(pvt->regs + reg);
 }
@@ -149,6 +153,25 @@ static inline u32 pvt_readl_relaxed(struct pvt_hwmon const *pvt, int reg) {
 static inline void pvt_writel(u32 data, struct pvt_hwmon const *pvt, int reg) {
 	writel(data, pvt->regs + reg);
 }
+#else
+static inline u32 pvt_readl(struct pvt_hwmon const *pvt, int reg) {
+	struct arm_smccc_res res;
+	arm_smccc_smc(BAIKAL_SMC_PVT_ID, PVT_READ, pvt->pvt_id, reg,
+		      0, 0, 0, 0, &res);
+	return res.a0;
+}
+
+static inline u32 pvt_readl_relaxed(struct pvt_hwmon const *pvt, int reg) {
+	return pvt_readl(pvt, reg);
+}
+
+static inline void pvt_writel(u32 data, struct pvt_hwmon const *pvt, int reg) {
+	struct arm_smccc_res res;
+	arm_smccc_smc(BAIKAL_SMC_PVT_ID, PVT_WRITE, pvt->pvt_id, reg,
+		      data, 0, 0, 0, &res);
+}
+#endif
+
 static inline u32 pvt_update(struct pvt_hwmon *pvt, int reg, u32 mask, u32 data)
 {
 	u32 old;
diff --git a/drivers/hwmon/bt1-pvt.h b/drivers/hwmon/bt1-pvt.h
index 93b8dd5e7c94..0cea95b01c13 100644
--- a/drivers/hwmon/bt1-pvt.h
+++ b/drivers/hwmon/bt1-pvt.h
@@ -101,6 +101,13 @@
 # define PVT_TOUT_DEF		0
 #endif
 
+#define BAIKAL_SMC_PVT_ID 0x82000001
+#define PVT_READ 0
+#define PVT_WRITE 1
+#ifndef CONFIG_ARM64
+#define BT1_PVT_DIRECT_REG_ACCESS
+#endif
+
 /*
  * enum pvt_sensor_type - Baikal-T1 PVT sensor types (correspond to each PVT
  *			  sampling mode)
@@ -217,6 +224,7 @@ struct pvt_hwmon {
 	enum pvt_sensor_type sensor;
 	struct pvt_cache cache[PVT_SENSORS_NUM];
 	ktime_t timeout;
+	int pvt_id;
 };
 
 /*
-- 
2.32.0