[PATCH 1/2] clocksource/drivers/imx-tpm: correct some registers operation flow

From: Anson Huang
Date: Mon Mar 26 2018 - 03:51:04 EST


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;

Replace incorret clock name igp with ipg.

Signed-off-by: Anson Huang <Anson.Huang@xxxxxxx>
---
Documentation/devicetree/bindings/timer/nxp,tpm-timer.txt | 2 +-
drivers/clocksource/timer-imx-tpm.c | 10 ++++++++--
2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/timer/nxp,tpm-timer.txt b/Documentation/devicetree/bindings/timer/nxp,tpm-timer.txt
index b4aa7dd..f82087b 100644
--- a/Documentation/devicetree/bindings/timer/nxp,tpm-timer.txt
+++ b/Documentation/devicetree/bindings/timer/nxp,tpm-timer.txt
@@ -15,7 +15,7 @@ Required properties:
- interrupts : Should be the clock event device interrupt.
- clocks : The clocks provided by the SoC to drive the timer, must contain
an entry for each entry in clock-names.
-- clock-names : Must include the following entries: "igp" and "per".
+- clock-names : Must include the following entries: "ipg" and "per".

Example:
tpm5: tpm@40260000 {
diff --git a/drivers/clocksource/timer-imx-tpm.c b/drivers/clocksource/timer-imx-tpm.c
index 21bffdc..7403e49 100644
--- 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;
@@ -179,7 +181,7 @@ static int __init tpm_timer_init(struct device_node *np)
ipg = of_clk_get_by_name(np, "ipg");
per = of_clk_get_by_name(np, "per");
if (IS_ERR(ipg) || IS_ERR(per)) {
- pr_err("tpm: failed to get igp or per clk\n");
+ pr_err("tpm: failed to get ipg or per clk\n");
ret = -ENODEV;
goto err_clk_get;
}
@@ -205,9 +207,13 @@ static int __init tpm_timer_init(struct device_node *np)
* 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,
--
2.7.4