Re: [PATCH v2 1/6] rtc: omap: kicker mechanism support
From: Sergei Shtylyov <hidden>
Date: 2012-07-25 11:16:28
Hello. On 25-07-2012 10:12, Afzal Mohammed wrote:
OMAP RTC IP can have kicker feature. This prevents spurious writes to register. To write to registers kicker lock has to be released. Procedure to do it as follows,
1. write to kick0 register, 0x83e70b13 2. write to kick1 register, 0x95a4f1e0
Writing value other than 0x83e70b13 to kick0 enables write locking, more details about kicker mechanism can be found in section 20.3.3.5.3 of AM335X TRM @www.ti.com/am335x
Here id table information is added and is used to distinguish those that require kicker handling and the ones that doesn't need it. There are more features in the newer IP's compared to legacy ones other than kicker, which driver currently doesn't handle, supporting additional features would be easier with the addition of id table.
Older IP (of OMAP1) doesn't have revision register as per TRM, so revision register can't be relied always to find features, hence id table is being used.
Signed-off-by: Afzal Mohammed <redacted> ---
v2: Use device name da830-rtc instead of am1808-rtc Newly added register name made similar to that existing in the driver Better commit message description
drivers/rtc/rtc-omap.c | 39 ++++++++++++++++++++++++++++++++++++++- 1 files changed, 38 insertions(+), 1 deletions(-)
quoted hunk
diff --git a/drivers/rtc/rtc-omap.c b/drivers/rtc/rtc-omap.c index 0b614e3..8afbc2e 100644 --- a/drivers/rtc/rtc-omap.c +++ b/drivers/rtc/rtc-omap.c@@ -38,6 +38,8 @@ * the SoC). See the BOARD-SPECIFIC CUSTOMIZATION comment. */ +#define DRIVER_NAME "omap_rtc" + #define OMAP_RTC_BASE 0xfffb4800 /* RTC registers */@@ -64,6 +66,9 @@ #define OMAP_RTC_COMP_MSB_REG 0x50 #define OMAP_RTC_OSC_REG 0x54 +#define OMAP_RTC_KICK0_REG 0x6c +#define OMAP_RTC_KICK1_REG 0x70 + /* OMAP_RTC_CTRL_REG bit fields: */ #define OMAP_RTC_CTRL_SPLIT (1<<7) #define OMAP_RTC_CTRL_DISABLE (1<<6)@@ -88,11 +93,19 @@ #define OMAP_RTC_INTERRUPTS_IT_ALARM (1<<3) #define OMAP_RTC_INTERRUPTS_IT_TIMER (1<<2) +/* OMAP_RTC_KICKER values */ +#define KICK0_VALUE (0x83e70b13) +#define KICK1_VALUE (0x95a4f1e0)
Parens not needed around simple literals.
static void __iomem *rtc_base; #define rtc_read(addr) __raw_readb(rtc_base + (addr)) #define rtc_write(val, addr) __raw_writeb(val, rtc_base + (addr)) +#define rtc_writel(val, addr) writel(val, rtc_base + (addr)) +
Why not __raw_writel() like the above functions?
WBR, Sergei