diff options
Diffstat (limited to 'drivers/rtc/rtc-ds1302.c')
| -rw-r--r-- | drivers/rtc/rtc-ds1302.c | 85 |
1 files changed, 67 insertions, 18 deletions
diff --git a/drivers/rtc/rtc-ds1302.c b/drivers/rtc/rtc-ds1302.c index 532acf9b05d..359d1e04626 100644 --- a/drivers/rtc/rtc-ds1302.c +++ b/drivers/rtc/rtc-ds1302.c @@ -16,7 +16,6 @@ #include <linux/rtc.h> #include <linux/io.h> #include <linux/bcd.h> -#include <asm/rtc.h> #define DRV_NAME "rtc-ds1302" #define DRV_VERSION "0.1.1" @@ -34,14 +33,55 @@ #define RTC_ADDR_MIN 0x01 /* Address of minute register */ #define RTC_ADDR_SEC 0x00 /* Address of second register */ +#ifdef CONFIG_SH_SECUREEDGE5410 +#include <asm/rtc.h> +#include <mach/snapgear.h> + #define RTC_RESET 0x1000 #define RTC_IODATA 0x0800 #define RTC_SCLK 0x0400 -#ifdef CONFIG_SH_SECUREEDGE5410 -#include <mach/snapgear.h> #define set_dp(x) SECUREEDGE_WRITE_IOPORT(x, 0x1c00) #define get_dp() SECUREEDGE_READ_IOPORT() +#define ds1302_set_tx() +#define ds1302_set_rx() + +static inline int ds1302_hw_init(void) +{ + return 0; +} + +static inline void ds1302_reset(void) +{ + set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK)); +} + +static inline void ds1302_clock(void) +{ + set_dp(get_dp() | RTC_SCLK); /* clock high */ + set_dp(get_dp() & ~RTC_SCLK); /* clock low */ +} + +static inline void ds1302_start(void) +{ + set_dp(get_dp() | RTC_RESET); +} + +static inline void ds1302_stop(void) +{ + set_dp(get_dp() & ~RTC_RESET); +} + +static inline void ds1302_txbit(int bit) +{ + set_dp((get_dp() & ~RTC_IODATA) | (bit ? RTC_IODATA : 0)); +} + +static inline int ds1302_rxbit(void) +{ + return !!(get_dp() & RTC_IODATA); +} + #else #error "Add support for your platform" #endif @@ -50,11 +90,11 @@ static void ds1302_sendbits(unsigned int val) { int i; + ds1302_set_tx(); + for (i = 8; (i); i--, val >>= 1) { - set_dp((get_dp() & ~RTC_IODATA) | ((val & 0x1) ? - RTC_IODATA : 0)); - set_dp(get_dp() | RTC_SCLK); /* clock high */ - set_dp(get_dp() & ~RTC_SCLK); /* clock low */ + ds1302_txbit(val & 0x1); + ds1302_clock(); } } @@ -63,10 +103,11 @@ static unsigned int ds1302_recvbits(void) unsigned int val; int i; + ds1302_set_rx(); + for (i = 0, val = 0; (i < 8); i++) { - val |= (((get_dp() & RTC_IODATA) ? 1 : 0) << i); - set_dp(get_dp() | RTC_SCLK); /* clock high */ - set_dp(get_dp() & ~RTC_SCLK); /* clock low */ + val |= (ds1302_rxbit() << i); + ds1302_clock(); } return val; @@ -76,23 +117,24 @@ static unsigned int ds1302_readbyte(unsigned int addr) { unsigned int val; - set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK)); + ds1302_reset(); - set_dp(get_dp() | RTC_RESET); + ds1302_start(); ds1302_sendbits(((addr & 0x3f) << 1) | RTC_CMD_READ); val = ds1302_recvbits(); - set_dp(get_dp() & ~RTC_RESET); + ds1302_stop(); return val; } static void ds1302_writebyte(unsigned int addr, unsigned int val) { - set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK)); - set_dp(get_dp() | RTC_RESET); + ds1302_reset(); + + ds1302_start(); ds1302_sendbits(((addr & 0x3f) << 1) | RTC_CMD_WRITE); ds1302_sendbits(val); - set_dp(get_dp() & ~RTC_RESET); + ds1302_stop(); } static int ds1302_rtc_read_time(struct device *dev, struct rtc_time *tm) @@ -167,13 +209,20 @@ static int __init ds1302_rtc_probe(struct platform_device *pdev) { struct rtc_device *rtc; + if (ds1302_hw_init()) { + dev_err(&pdev->dev, "Failed to init communication channel"); + return -EINVAL; + } + /* Reset */ - set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK)); + ds1302_reset(); /* Write a magic value to the DS1302 RAM, and see if it sticks. */ ds1302_writebyte(RTC_ADDR_RAM0, 0x42); - if (ds1302_readbyte(RTC_ADDR_RAM0) != 0x42) + if (ds1302_readbyte(RTC_ADDR_RAM0) != 0x42) { + dev_err(&pdev->dev, "Failed to probe"); return -ENODEV; + } rtc = rtc_device_register("ds1302", &pdev->dev, &ds1302_rtc_ops, THIS_MODULE); |