clocksource/drivers/moxart: Add Aspeed support

The Aspeed SoC has timer IP with a very similar register layout to the
moxart timer. This patch adds support for the fourth and fifth gen
aspeed SoCs, and has been tested on the ast2400 and ast2500.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

1 files changed, 32 insertions, 0 deletions

diff --git a/drivers/clocksource/moxart_timer.c b/drivers/clocksource/moxart_timer.c
index cb0b34786a8e..ad2bead9ce45 100644
--- a/drivers/clocksource/moxart_timer.c
+++ b/drivers/clocksource/moxart_timer.c
@@ -56,6 +56,23 @@
 #define MOXART_TIMER1_ENABLE    (MOXART_CR_2_ENABLE | MOXART_CR_1_ENABLE)
 #define MOXART_TIMER1_DISABLE   (MOXART_CR_2_ENABLE)
 
+/*
+ * The ASpeed variant of the IP block has a different layout
+ * for the control register
+ */
+#define ASPEED_CR_1_ENABLE      BIT(0)
+#define ASPEED_CR_1_CLOCK       BIT(1)
+#define ASPEED_CR_1_INT         BIT(2)
+#define ASPEED_CR_2_ENABLE      BIT(4)
+#define ASPEED_CR_2_CLOCK       BIT(5)
+#define ASPEED_CR_2_INT         BIT(6)
+#define ASPEED_CR_3_ENABLE      BIT(8)
+#define ASPEED_CR_3_CLOCK       BIT(9)
+#define ASPEED_CR_3_INT         BIT(10)
+
+#define ASPEED_TIMER1_ENABLE   (ASPEED_CR_2_ENABLE | ASPEED_CR_1_ENABLE)
+#define ASPEED_TIMER1_DISABLE  (ASPEED_CR_2_ENABLE)
+
 struct moxart_timer {
         void __iomem *base;
         unsigned int t1_disable_val;
@@ -165,6 +182,9 @@ static int __init moxart_timer_init(struct device_node *node)
         if (of_device_is_compatible(node, "moxa,moxart-timer")) {
                 timer->t1_enable_val = MOXART_TIMER1_ENABLE;
                 timer->t1_disable_val = MOXART_TIMER1_DISABLE;
+        } else if (of_device_is_compatible(node, "aspeed,ast2400-timer")) {
+                timer->t1_enable_val = ASPEED_TIMER1_ENABLE;
+                timer->t1_disable_val = ASPEED_TIMER1_DISABLE;
         } else
                 panic("%s: unknown platform\n", node->full_name);
 
@@ -200,6 +220,17 @@ static int __init moxart_timer_init(struct device_node *node)
                 return ret;
         }
 
+        /* Clear match registers */
+        writel(0, timer->base + TIMER1_BASE + REG_MATCH1);
+        writel(0, timer->base + TIMER1_BASE + REG_MATCH2);
+        writel(0, timer->base + TIMER2_BASE + REG_MATCH1);
+        writel(0, timer->base + TIMER2_BASE + REG_MATCH2);
+
+        /*
+         * Start timer 2 rolling as our main wall clock source, keep timer 1
+         * disabled
+         */
+        writel(0, timer->base + TIMER_CR);
         writel(~0, timer->base + TIMER2_BASE + REG_LOAD);
         writel(timer->t1_disable_val, timer->base + TIMER_CR);
 
@@ -214,3 +245,4 @@ static int __init moxart_timer_init(struct device_node *node)
         return 0;
 }
 CLOCKSOURCE_OF_DECLARE(moxart, "moxa,moxart-timer", moxart_timer_init);
+CLOCKSOURCE_OF_DECLARE(aspeed, "aspeed,ast2400-timer", moxart_timer_init);