clocksource/drivers/imx-sysctr: Add i.MX95 support

To i.MX95 System counter module, we use Read register space to get
the counter, not the Control register space to get the counter, because
System Manager firmware not allow Linux to read Control register space,
so add a new TIMER_OF_DECLARE entry for i.MX95.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20240205-imx-sysctr-v4-3-ca5a6e1552e7@nxp.com

Author: MrVan

drivers/clocksource/timer-imx-sysctr.c

@@ -9,12 +9,15 @@
 #include "timer-of.h"
 
 #define CMP_OFFSET	0x10000
+#define RD_OFFSET	0x20000
 
 #define CNTCV_LO	0x8
 #define CNTCV_HI	0xc
 #define CMPCV_LO	(CMP_OFFSET + 0x20)
 #define CMPCV_HI	(CMP_OFFSET + 0x24)
 #define CMPCR		(CMP_OFFSET + 0x2c)
+#define CNTCV_LO_IMX95	(RD_OFFSET + 0x8)
+#define CNTCV_HI_IMX95	(RD_OFFSET + 0xc)
 
 #define SYS_CTR_EN		0x1
 #define SYS_CTR_IRQ_MASK	0x2
@@ -23,6 +26,8 @@
 
 struct sysctr_private {
 	u32 cmpcr;
+	u32 lo_off;
+	u32 hi_off;
 };
 
 static void sysctr_timer_enable(struct clock_event_device *evt, bool enable)
@@ -47,13 +52,14 @@ static void sysctr_irq_acknowledge(struct clock_event_device *evt)
 static inline u64 sysctr_read_counter(struct clock_event_device *evt)
 {
 	struct timer_of *to = to_timer_of(evt);
+	struct sysctr_private *priv = to->private_data;
 	void __iomem *base = timer_of_base(to);
 	u32 cnt_hi, tmp_hi, cnt_lo;
 
 	do {
-		cnt_hi = readl_relaxed(base + CNTCV_HI);
-		cnt_lo = readl_relaxed(base + CNTCV_LO);
-		tmp_hi = readl_relaxed(base + CNTCV_HI);
+		cnt_hi = readl_relaxed(base + priv->hi_off);
+		cnt_lo = readl_relaxed(base + priv->lo_off);
+		tmp_hi = readl_relaxed(base + priv->hi_off);
 	} while (tmp_hi != cnt_hi);
 
 	return  ((u64) cnt_hi << 32) | cnt_lo;
@@ -127,7 +133,7 @@ static struct timer_of to_sysctr = {
 	},
 };
 
-static int __init sysctr_timer_init(struct device_node *np)
+static int __init __sysctr_timer_init(struct device_node *np)
 {
 	struct sysctr_private *priv;
 	void __iomem *base;
@@ -154,9 +160,48 @@ static int __init sysctr_timer_init(struct device_node *np)
 	base = timer_of_base(&to_sysctr);
 	priv->cmpcr = readl(base + CMPCR) & ~SYS_CTR_EN;
 
+	return 0;
+}
+
+static int __init sysctr_timer_init(struct device_node *np)
+{
+	struct sysctr_private *priv;
+	int ret;
+
+	ret = __sysctr_timer_init(np);
+	if (ret)
+		return ret;
+
+	priv = to_sysctr.private_data;
+	priv->lo_off = CNTCV_LO;
+	priv->hi_off = CNTCV_HI;
+
 	clockevents_config_and_register(&to_sysctr.clkevt,
 					timer_of_rate(&to_sysctr),
 					0xff, 0x7fffffff);
+
 	return 0;
 }
+
+static int __init sysctr_timer_imx95_init(struct device_node *np)
+{
+	struct sysctr_private *priv;
+	int ret;
+
+	ret = __sysctr_timer_init(np);
+	if (ret)
+		return ret;
+
+	priv = to_sysctr.private_data;
+	priv->lo_off = CNTCV_LO_IMX95;
+	priv->hi_off = CNTCV_HI_IMX95;
+
+	clockevents_config_and_register(&to_sysctr.clkevt,
+					timer_of_rate(&to_sysctr),
+					0xff, 0x7fffffff);
+
+	return 0;
+}
+
 TIMER_OF_DECLARE(sysctr_timer, "nxp,sysctr-timer", sysctr_timer_init);
+TIMER_OF_DECLARE(sysctr_timer_imx95, "nxp,imx95-sysctr-timer", sysctr_timer_imx95_init);