diff options
| -rw-r--r-- | Documentation/devicetree/bindings/rtc/sun6i-rtc.txt | 10 | ||||
| -rw-r--r-- | drivers/rtc/rtc-sun6i.c | 146 |
2 files changed, 143 insertions, 13 deletions
diff --git a/Documentation/devicetree/bindings/rtc/sun6i-rtc.txt b/Documentation/devicetree/bindings/rtc/sun6i-rtc.txt index f007e428a1ab..945934918b71 100644 --- a/Documentation/devicetree/bindings/rtc/sun6i-rtc.txt +++ b/Documentation/devicetree/bindings/rtc/sun6i-rtc.txt @@ -8,10 +8,20 @@ Required properties: memory mapped region. - interrupts : IRQ lines for the RTC alarm 0 and alarm 1, in that order. +Required properties for new device trees +- clocks : phandle to the 32kHz external oscillator +- clock-output-names : name of the LOSC clock created +- #clock-cells : must be equals to 1. The RTC provides two clocks: the + LOSC and its external output, with index 0 and 1 + respectively. + Example: rtc: rtc@01f00000 { compatible = "allwinner,sun6i-a31-rtc"; reg = <0x01f00000 0x54>; interrupts = <0 40 4>, <0 41 4>; + clock-output-names = "osc32k"; + clocks = <&ext_osc32k>; + #clock-cells = <1>; }; diff --git a/drivers/rtc/rtc-sun6i.c b/drivers/rtc/rtc-sun6i.c index b0d45d23a11b..37f65c50ab2d 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> @@ -33,6 +35,7 @@ #include <linux/of_device.h> #include <linux/platform_device.h> #include <linux/rtc.h> +#include <linux/slab.h> #include <linux/types.h> /* Control register */ @@ -44,6 +47,8 @@ #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 @@ -117,9 +122,134 @@ struct sun6i_rtc_dev { 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 (!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); + + /* 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); + + /* Yes, I know, this is ugly. */ + sun6i_rtc = rtc; +} +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; @@ -363,23 +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; - spin_lock_init(&chip->lock); + 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"); @@ -419,9 +541,7 @@ static int sun6i_rtc_probe(struct platform_device *pdev) /* disable alarm wakeup */ writel(0, chip->base + SUN6I_ALARM_CONFIG); - /* switch to the external, more precise, oscillator */ - writel(SUN6I_LOSC_CTRL_KEY | SUN6I_LOSC_CTRL_EXT_OSC, - chip->base + SUN6I_LOSC_CTRL); + clk_prepare_enable(chip->losc); chip->rtc = rtc_device_register("rtc-sun6i", &pdev->dev, &sun6i_rtc_ops, THIS_MODULE); |