[v4,09/21] rtc: support DS1302 RTC on ICP DAS LP-8x4x

Alexandre Belloni
2015-06-08T12:07:13Z

Hi Sergey,

Are you still interested in seeing that patch going upstream?

On 16/04/2014 at 21:17:14 +0400, Sergey Yanovich wrote :
> Signed-off-by: Sergei Ianovich <ynvich@gmail.com>
> ---
> v3..v4
> * move DTS bindings to a different patch (8/21)
>
> v2..v3
> * use usleep_range instead of custom nsleep
> * number change (07/16 -> 09/21)
>
> v0..v2
> * use device tree
> * use devm helpers where possible
>
> .../devicetree/bindings/rtc/rtc-ds1302.txt | 14 +++
> arch/arm/configs/lp8x4x_defconfig | 1 +
> drivers/rtc/Kconfig | 2 +-
> drivers/rtc/rtc-ds1302.c | 100 ++++++++++++++++++++-
> 4 files changed, 114 insertions(+), 3 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/rtc/rtc-ds1302.txt
>
> diff --git a/Documentation/devicetree/bindings/rtc/rtc-ds1302.txt b/Documentation/devicetree/bindings/rtc/rtc-ds1302.txt
> new file mode 100644
> index 0000000..810613b
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/rtc/rtc-ds1302.txt
> @@ -0,0 +1,14 @@
> +* Dallas Semiconductor DS-1302 RTC
> +
> +Simple device which could be used to store date/time between reboots.
> +
> +Required properties:
> +- compatible : Should be "dallas,rtc-ds1302"
> +- reg : Should be address and size of IO memory region
> +
> +Examples:
> +
> +rtc at 40900000 {
> + compatible = "dallas,rtc-ds1302";
> + reg = <0x1700901c 0x1>;
> +};
> diff --git a/arch/arm/configs/lp8x4x_defconfig b/arch/arm/configs/lp8x4x_defconfig
> index 9f1efb6..d60e37a 100644
> --- a/arch/arm/configs/lp8x4x_defconfig
> +++ b/arch/arm/configs/lp8x4x_defconfig
> @@ -141,6 +141,7 @@ CONFIG_LEDS_GPIO=y
> CONFIG_LEDS_TRIGGERS=y
> CONFIG_LEDS_TRIGGER_HEARTBEAT=y
> CONFIG_RTC_CLASS=y
> +CONFIG_RTC_DRV_DS1302=y
> CONFIG_RTC_DRV_PXA=m
> # CONFIG_IOMMU_SUPPORT is not set
> CONFIG_EXT2_FS=m
> diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
> index 2e565f8..80aaaa1 100644
> --- a/drivers/rtc/Kconfig
> +++ b/drivers/rtc/Kconfig
> @@ -710,7 +710,7 @@ config RTC_DRV_DS1286
>
> config RTC_DRV_DS1302
> tristate "Dallas DS1302"
> - depends on SH_SECUREEDGE5410
> + depends on SH_SECUREEDGE5410 || (ARCH_PXA && HIGH_RES_TIMERS)
> help
> If you say yes here you get support for the Dallas DS1302 RTC chips.
>
> diff --git a/drivers/rtc/rtc-ds1302.c b/drivers/rtc/rtc-ds1302.c
> index 07e8d79..3c49023 100644
> --- a/drivers/rtc/rtc-ds1302.c
> +++ b/drivers/rtc/rtc-ds1302.c
> @@ -50,7 +50,7 @@
> #define ds1302_set_tx()
> #define ds1302_set_rx()
>
> -static inline int ds1302_hw_init(void)
> +static inline int ds1302_hw_init(struct platform_device *pdev)
> {
> return 0;
> }
> @@ -86,6 +86,101 @@ static inline int ds1302_rxbit(void)
> return !!(get_dp() & RTC_IODATA);
> }
>
> +#elif defined(CONFIG_ARCH_PXA) && defined(CONFIG_HIGH_RES_TIMERS)
> +
> +#include <linux/delay.h>
> +#include <linux/of.h>
> +
> +#define RTC_CE 0x01
> +#define RTC_CLK 0x02
> +#define RTC_nWE 0x04
> +#define RTC_IODATA 0x08
> +
> +static unsigned long ds1302_state;
> +
> +static void *mem;
> +
> +static inline int ds1302_hw_init(struct platform_device *pdev)
> +{
> + struct resource *r;
> +
> + r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!r)
> + return -ENODEV;
> +
> + mem = devm_ioremap_resource(&pdev->dev, r);
> + if (!mem)
> + return -EFAULT;
> +
> + return 0;
> +}
> +
> +static inline void ds1302_reset(void)
> +{
> + ds1302_state = 0;
> + iowrite8(ds1302_state, mem);
> + usleep_range(4, 5);
> +}
> +
> +static inline void ds1302_clock(void)
> +{
> + usleep_range(1, 2);
> + ds1302_state |= RTC_CLK;
> + iowrite8(ds1302_state, mem);
> + usleep_range(1, 2);
> + ds1302_state &= ~RTC_CLK;
> + iowrite8(ds1302_state, mem);
> +}
> +
> +static inline void ds1302_start(void)
> +{
> + ds1302_state &= ~RTC_CLK;
> + ds1302_state |= RTC_CE;
> + iowrite8(ds1302_state, mem);
> + usleep_range(3, 4);
> +}
> +
> +static inline void ds1302_stop(void)
> +{
> + ds1302_state &= ~RTC_CE;
> + iowrite8(ds1302_state, mem);
> +}
> +
> +static inline void ds1302_set_tx(void)
> +{
> + ds1302_state &= ~RTC_nWE;
> + iowrite8(ds1302_state, mem);
> +}
> +
> +static inline void ds1302_set_rx(void)
> +{
> + ds1302_state |= RTC_nWE;
> + iowrite8(ds1302_state, mem);
> +}
> +
> +static inline void ds1302_txbit(int bit)
> +{
> + if (bit)
> + ds1302_state |= RTC_IODATA;
> + else
> + ds1302_state &= ~RTC_IODATA;
> + iowrite8(ds1302_state, mem);
> +}
> +
> +static inline int ds1302_rxbit(void)
> +{
> + return ioread8(mem) & 0x1;
> +}
> +
> +#ifdef CONFIG_OF
> +static const struct of_device_id ds1302_dt_ids[] = {
> + { .compatible = "dallas,rtc-ds1302" },
> + { }
> +};
> +
> +MODULE_DEVICE_TABLE(of, ds1302_dt_ids);
> +#endif
> +
> #else
> #error "Add support for your platform"
> #endif
> @@ -216,7 +311,7 @@ static int __init ds1302_rtc_probe(struct platform_device *pdev)
> {
> struct rtc_device *rtc;
>
> - if (ds1302_hw_init()) {
> + if (ds1302_hw_init(pdev)) {
> dev_err(&pdev->dev, "Failed to init communication channel");
> return -EINVAL;
> }
> @@ -245,6 +340,7 @@ static struct platform_driver ds1302_platform_driver = {
> .driver = {
> .name = DRV_NAME,
> .owner = THIS_MODULE,
> + .of_match_table = of_match_ptr(ds1302_dt_ids),
> },
> };
>

--
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering