[PATCH 4.14 001/189] clocksource/drivers/imx-tpm: Correct some registers operation flow

Greg Kroah-Hartman
2018-06-18T09:15:20Z

From: Anson Huang <Anson.Huang@nxp.com>

[ Upstream commit 506a7be93ff773d5d4cf75a59f342865605b4910 ]

According to i.MX7ULP reference manual, TPM_SC_CPWMS can ONLY be written when
counter is disabled, TPM_SC_TOF is write-1-clear, TPM_C0SC_CHF is also
write-1-clear, correct these registers initialization flow;

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/clocksource/timer-imx-tpm.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

--- a/drivers/clocksource/timer-imx-tpm.c
+++ b/drivers/clocksource/timer-imx-tpm.c
@@ -20,6 +20,7 @@
#define TPM_SC 0x10
#define TPM_SC_CMOD_INC_PER_CNT (0x1 << 3)
#define TPM_SC_CMOD_DIV_DEFAULT 0x3
+#define TPM_SC_TOF_MASK (0x1 << 7)
#define TPM_CNT 0x14
#define TPM_MOD 0x18
#define TPM_STATUS 0x1c
@@ -29,6 +30,7 @@
#define TPM_C0SC_MODE_SHIFT 2
#define TPM_C0SC_MODE_MASK 0x3c
#define TPM_C0SC_MODE_SW_COMPARE 0x4
+#define TPM_C0SC_CHF_MASK (0x1 << 7)
#define TPM_C0V 0x24

static void __iomem *timer_base;
@@ -205,9 +207,13 @@ static int __init tpm_timer_init(struct
* 4) Channel0 disabled
* 5) DMA transfers disabled
*/
+ /* make sure counter is disabled */
writel(0, timer_base + TPM_SC);
+ /* TOF is W1C */
+ writel(TPM_SC_TOF_MASK, timer_base + TPM_SC);
writel(0, timer_base + TPM_CNT);
- writel(0, timer_base + TPM_C0SC);
+ /* CHF is W1C */
+ writel(TPM_C0SC_CHF_MASK, timer_base + TPM_C0SC);

/* increase per cnt, div 8 by default */
writel(TPM_SC_CMOD_INC_PER_CNT | TPM_SC_CMOD_DIV_DEFAULT,