rtc: omap: Support scratch registers

Register an nvmem device to expose the 3 scratch registers (total of 12
bytes) to both userspace and kernel space.

Reviewed-by: Sekhar Nori <nsekhar@ti.com>
Tested-by: Keerthy <j-keerthy@ti.com>
Reviewed-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

diff --git a/drivers/rtc/rtc-omap.c b/drivers/rtc/rtc-omap.c
index d56d937..1d666ac 100644 (file)
--- a/drivers/rtc/rtc-omap.c
+++ b/drivers/rtc/rtc-omap.c
@@ -70,6 +70,10 @@
 #define OMAP_RTC_COMP_MSB_REG          0x50
 #define OMAP_RTC_OSC_REG               0x54
 
+#define OMAP_RTC_SCRATCH0_REG          0x60
+#define OMAP_RTC_SCRATCH1_REG          0x64
+#define OMAP_RTC_SCRATCH2_REG          0x68
+
 #define OMAP_RTC_KICK0_REG             0x6c
 #define OMAP_RTC_KICK1_REG             0x70
 
@@ -667,6 +671,45 @@ static struct pinctrl_desc rtc_pinctrl_desc = {
        .owner = THIS_MODULE,
 };
 
+static int omap_rtc_scratch_read(void *priv, unsigned int offset, void *_val,
+                                size_t bytes)
+{
+       struct omap_rtc *rtc = priv;
+       u32 *val = _val;
+       int i;
+
+       for (i = 0; i < bytes / 4; i++)
+               val[i] = rtc_readl(rtc,
+                                  OMAP_RTC_SCRATCH0_REG + offset + (i * 4));
+
+       return 0;
+}
+
+static int omap_rtc_scratch_write(void *priv, unsigned int offset, void *_val,
+                                 size_t bytes)
+{
+       struct omap_rtc *rtc = priv;
+       u32 *val = _val;
+       int i;
+
+       rtc->type->unlock(rtc);
+       for (i = 0; i < bytes / 4; i++)
+               rtc_writel(rtc,
+                          OMAP_RTC_SCRATCH0_REG + offset + (i * 4), val[i]);
+       rtc->type->lock(rtc);
+
+       return 0;
+}
+
+static struct nvmem_config omap_rtc_nvmem_config = {
+       .name = "omap_rtc_scratch",
+       .word_size = 4,
+       .stride = 4,
+       .size = OMAP_RTC_KICK0_REG - OMAP_RTC_SCRATCH0_REG,
+       .reg_read = omap_rtc_scratch_read,
+       .reg_write = omap_rtc_scratch_write,
+};
+
 static int omap_rtc_probe(struct platform_device *pdev)
 {
        struct omap_rtc *rtc;
@@ -804,6 +847,8 @@ static int omap_rtc_probe(struct platform_device *pdev)
        }
 
        rtc->rtc->ops = &omap_rtc_ops;
+       omap_rtc_nvmem_config.priv = rtc;
+       rtc->rtc->nvmem_config = &omap_rtc_nvmem_config;
 
        /* handle periodic and alarm irqs */
        ret = devm_request_irq(&pdev->dev, rtc->irq_timer, rtc_irq, 0,