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path: root/drivers/rtc/rtc-sun6i.c
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Diffstat (limited to 'drivers/rtc/rtc-sun6i.c')
-rw-r--r--drivers/rtc/rtc-sun6i.c182
1 files changed, 153 insertions, 29 deletions
diff --git a/drivers/rtc/rtc-sun6i.c b/drivers/rtc/rtc-sun6i.c
index c169a2cd4727..39cbc1238b92 100644
--- a/drivers/rtc/rtc-sun6i.c
+++ b/drivers/rtc/rtc-sun6i.c
@@ -20,6 +20,8 @@
* more details.
*/
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/fs.h>
@@ -33,15 +35,20 @@
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
+#include <linux/slab.h>
#include <linux/types.h>
/* Control register */
#define SUN6I_LOSC_CTRL 0x0000
+#define SUN6I_LOSC_CTRL_KEY (0x16aa << 16)
#define SUN6I_LOSC_CTRL_ALM_DHMS_ACC BIT(9)
#define SUN6I_LOSC_CTRL_RTC_HMS_ACC BIT(8)
#define SUN6I_LOSC_CTRL_RTC_YMD_ACC BIT(7)
+#define SUN6I_LOSC_CTRL_EXT_OSC BIT(0)
#define SUN6I_LOSC_CTRL_ACC_MASK GENMASK(9, 7)
+#define SUN6I_LOSC_CLK_PRESCAL 0x0008
+
/* RTC */
#define SUN6I_RTC_YMD 0x0010
#define SUN6I_RTC_HMS 0x0014
@@ -114,13 +121,142 @@ struct sun6i_rtc_dev {
void __iomem *base;
int irq;
unsigned long alarm;
+
+ struct clk_hw hw;
+ struct clk_hw *int_osc;
+ struct clk *losc;
+
+ spinlock_t lock;
+};
+
+static struct sun6i_rtc_dev *sun6i_rtc;
+
+static unsigned long sun6i_rtc_osc_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct sun6i_rtc_dev *rtc = container_of(hw, struct sun6i_rtc_dev, hw);
+ u32 val;
+
+ val = readl(rtc->base + SUN6I_LOSC_CTRL);
+ if (val & SUN6I_LOSC_CTRL_EXT_OSC)
+ return parent_rate;
+
+ val = readl(rtc->base + SUN6I_LOSC_CLK_PRESCAL);
+ val &= GENMASK(4, 0);
+
+ return parent_rate / (val + 1);
+}
+
+static u8 sun6i_rtc_osc_get_parent(struct clk_hw *hw)
+{
+ struct sun6i_rtc_dev *rtc = container_of(hw, struct sun6i_rtc_dev, hw);
+
+ return readl(rtc->base + SUN6I_LOSC_CTRL) & SUN6I_LOSC_CTRL_EXT_OSC;
+}
+
+static int sun6i_rtc_osc_set_parent(struct clk_hw *hw, u8 index)
+{
+ struct sun6i_rtc_dev *rtc = container_of(hw, struct sun6i_rtc_dev, hw);
+ unsigned long flags;
+ u32 val;
+
+ if (index > 1)
+ return -EINVAL;
+
+ spin_lock_irqsave(&rtc->lock, flags);
+ val = readl(rtc->base + SUN6I_LOSC_CTRL);
+ val &= ~SUN6I_LOSC_CTRL_EXT_OSC;
+ val |= SUN6I_LOSC_CTRL_KEY;
+ val |= index ? SUN6I_LOSC_CTRL_EXT_OSC : 0;
+ writel(val, rtc->base + SUN6I_LOSC_CTRL);
+ spin_unlock_irqrestore(&rtc->lock, flags);
+
+ return 0;
+}
+
+static const struct clk_ops sun6i_rtc_osc_ops = {
+ .recalc_rate = sun6i_rtc_osc_recalc_rate,
+
+ .get_parent = sun6i_rtc_osc_get_parent,
+ .set_parent = sun6i_rtc_osc_set_parent,
};
+static void __init sun6i_rtc_clk_init(struct device_node *node)
+{
+ struct clk_hw_onecell_data *clk_data;
+ struct sun6i_rtc_dev *rtc;
+ struct clk_init_data init = {
+ .ops = &sun6i_rtc_osc_ops,
+ };
+ const char *parents[2];
+
+ rtc = kzalloc(sizeof(*rtc), GFP_KERNEL);
+ if (!rtc)
+ return;
+ spin_lock_init(&rtc->lock);
+
+ clk_data = kzalloc(sizeof(*clk_data) + sizeof(*clk_data->hws),
+ GFP_KERNEL);
+ if (!clk_data)
+ return;
+ spin_lock_init(&rtc->lock);
+
+ rtc->base = of_io_request_and_map(node, 0, of_node_full_name(node));
+ if (IS_ERR(rtc->base)) {
+ pr_crit("Can't map RTC registers");
+ return;
+ }
+
+ /* Switch to the external, more precise, oscillator */
+ writel(SUN6I_LOSC_CTRL_KEY | SUN6I_LOSC_CTRL_EXT_OSC,
+ rtc->base + SUN6I_LOSC_CTRL);
+
+ /* Yes, I know, this is ugly. */
+ sun6i_rtc = rtc;
+
+ /* Deal with old DTs */
+ if (!of_get_property(node, "clocks", NULL))
+ return;
+
+ rtc->int_osc = clk_hw_register_fixed_rate_with_accuracy(NULL,
+ "rtc-int-osc",
+ NULL, 0,
+ 667000,
+ 300000000);
+ if (IS_ERR(rtc->int_osc)) {
+ pr_crit("Couldn't register the internal oscillator\n");
+ return;
+ }
+
+ parents[0] = clk_hw_get_name(rtc->int_osc);
+ parents[1] = of_clk_get_parent_name(node, 0);
+
+ rtc->hw.init = &init;
+
+ init.parent_names = parents;
+ init.num_parents = of_clk_get_parent_count(node) + 1;
+ of_property_read_string(node, "clock-output-names", &init.name);
+
+ rtc->losc = clk_register(NULL, &rtc->hw);
+ if (IS_ERR(rtc->losc)) {
+ pr_crit("Couldn't register the LOSC clock\n");
+ return;
+ }
+
+ clk_data->num = 1;
+ clk_data->hws[0] = &rtc->hw;
+ of_clk_add_hw_provider(node, of_clk_hw_onecell_get, clk_data);
+}
+CLK_OF_DECLARE_DRIVER(sun6i_rtc_clk, "allwinner,sun6i-a31-rtc",
+ sun6i_rtc_clk_init);
+
static irqreturn_t sun6i_rtc_alarmirq(int irq, void *id)
{
struct sun6i_rtc_dev *chip = (struct sun6i_rtc_dev *) id;
+ irqreturn_t ret = IRQ_NONE;
u32 val;
+ spin_lock(&chip->lock);
val = readl(chip->base + SUN6I_ALRM_IRQ_STA);
if (val & SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND) {
@@ -129,10 +265,11 @@ static irqreturn_t sun6i_rtc_alarmirq(int irq, void *id)
rtc_update_irq(chip->rtc, 1, RTC_AF | RTC_IRQF);
- return IRQ_HANDLED;
+ ret = IRQ_HANDLED;
}
+ spin_unlock(&chip->lock);
- return IRQ_NONE;
+ return ret;
}
static void sun6i_rtc_setaie(int to, struct sun6i_rtc_dev *chip)
@@ -140,6 +277,7 @@ static void sun6i_rtc_setaie(int to, struct sun6i_rtc_dev *chip)
u32 alrm_val = 0;
u32 alrm_irq_val = 0;
u32 alrm_wake_val = 0;
+ unsigned long flags;
if (to) {
alrm_val = SUN6I_ALRM_EN_CNT_EN;
@@ -150,9 +288,11 @@ static void sun6i_rtc_setaie(int to, struct sun6i_rtc_dev *chip)
chip->base + SUN6I_ALRM_IRQ_STA);
}
+ spin_lock_irqsave(&chip->lock, flags);
writel(alrm_val, chip->base + SUN6I_ALRM_EN);
writel(alrm_irq_val, chip->base + SUN6I_ALRM_IRQ_EN);
writel(alrm_wake_val, chip->base + SUN6I_ALARM_CONFIG);
+ spin_unlock_irqrestore(&chip->lock, flags);
}
static int sun6i_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
@@ -191,11 +331,15 @@ static int sun6i_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
static int sun6i_rtc_getalarm(struct device *dev, struct rtc_wkalrm *wkalrm)
{
struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
+ unsigned long flags;
u32 alrm_st;
u32 alrm_en;
+ spin_lock_irqsave(&chip->lock, flags);
alrm_en = readl(chip->base + SUN6I_ALRM_IRQ_EN);
alrm_st = readl(chip->base + SUN6I_ALRM_IRQ_STA);
+ spin_unlock_irqrestore(&chip->lock, flags);
+
wkalrm->enabled = !!(alrm_en & SUN6I_ALRM_EN_CNT_EN);
wkalrm->pending = !!(alrm_st & SUN6I_ALRM_EN_CNT_EN);
rtc_time_to_tm(chip->alarm, &wkalrm->time);
@@ -349,22 +493,15 @@ static const struct rtc_class_ops sun6i_rtc_ops = {
static int sun6i_rtc_probe(struct platform_device *pdev)
{
- struct sun6i_rtc_dev *chip;
- struct resource *res;
+ struct sun6i_rtc_dev *chip = sun6i_rtc;
int ret;
- chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
if (!chip)
- return -ENOMEM;
+ return -ENODEV;
platform_set_drvdata(pdev, chip);
chip->dev = &pdev->dev;
- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- chip->base = devm_ioremap_resource(&pdev->dev, res);
- if (IS_ERR(chip->base))
- return PTR_ERR(chip->base);
-
chip->irq = platform_get_irq(pdev, 0);
if (chip->irq < 0) {
dev_err(&pdev->dev, "No IRQ resource\n");
@@ -404,8 +541,10 @@ static int sun6i_rtc_probe(struct platform_device *pdev)
/* disable alarm wakeup */
writel(0, chip->base + SUN6I_ALARM_CONFIG);
- chip->rtc = rtc_device_register("rtc-sun6i", &pdev->dev,
- &sun6i_rtc_ops, THIS_MODULE);
+ clk_prepare_enable(chip->losc);
+
+ chip->rtc = devm_rtc_device_register(&pdev->dev, "rtc-sun6i",
+ &sun6i_rtc_ops, THIS_MODULE);
if (IS_ERR(chip->rtc)) {
dev_err(&pdev->dev, "unable to register device\n");
return PTR_ERR(chip->rtc);
@@ -416,15 +555,6 @@ static int sun6i_rtc_probe(struct platform_device *pdev)
return 0;
}
-static int sun6i_rtc_remove(struct platform_device *pdev)
-{
- struct sun6i_rtc_dev *chip = platform_get_drvdata(pdev);
-
- rtc_device_unregister(chip->rtc);
-
- return 0;
-}
-
static const struct of_device_id sun6i_rtc_dt_ids[] = {
{ .compatible = "allwinner,sun6i-a31-rtc" },
{ /* sentinel */ },
@@ -433,15 +563,9 @@ MODULE_DEVICE_TABLE(of, sun6i_rtc_dt_ids);
static struct platform_driver sun6i_rtc_driver = {
.probe = sun6i_rtc_probe,
- .remove = sun6i_rtc_remove,
.driver = {
.name = "sun6i-rtc",
.of_match_table = sun6i_rtc_dt_ids,
},
};
-
-module_platform_driver(sun6i_rtc_driver);
-
-MODULE_DESCRIPTION("sun6i RTC driver");
-MODULE_AUTHOR("Chen-Yu Tsai <wens@csie.org>");
-MODULE_LICENSE("GPL");
+builtin_platform_driver(sun6i_rtc_driver);