On Sat, Apr 14, 2012 at 03:07:17PM +0800, Ying-Chun Liu (PaulLiu) wrote:
From: "Ying-Chun Liu (PaulLiu)" paul.liu@linaro.org
This adds an RTC driver for the Low Power (LP) section of SNVS. It hooks into the /dev/rtc interface and supports ioctl to complete RTC features. This driver supports device tree bindings. It only uses the RTC hw in non-secure mode.
Signed-off-by: Anish Trivedi anish@freescale.com Signed-off-by: Eric Miao eric.miao@linaro.org Signed-off-by: Anson Huang b20788@freescale.com Signed-off-by: Ying-Chun Liu (PaulLiu) paul.liu@linaro.org Cc: Alessandro Zummo a.zummo@towertech.it Cc: Shawn Guo shawn.guo@linaro.org Cc: Sascha Hauer s.hauer@pengutronix.de
Documentation/devicetree/bindings/rtc/snvs-rtc.txt | 18 + drivers/rtc/Kconfig | 10 + drivers/rtc/Makefile | 1 + drivers/rtc/rtc-snvs.c | 644 ++++++++++++++++++++ 4 files changed, 673 insertions(+) create mode 100644 Documentation/devicetree/bindings/rtc/snvs-rtc.txt create mode 100644 drivers/rtc/rtc-snvs.c
+#define CNTR_TO_SECS_SH 15 /* Converts 47-bit counter to 32-bit seconds */
+struct rtc_drv_data {
- struct rtc_device *rtc;
- void __iomem *ioaddr;
- int irq;
- bool irq_enable;
+};
+static DEFINE_SPINLOCK(rtc_lock);
Put this three lines above.
- writel(time >> (32 - CNTR_TO_SECS_SH), ioaddr + SNVS_LPSRTCMR);
- /* Enable RTC again */
- writel(lp_cr | SNVS_LPCR_SRTC_ENV, ioaddr + SNVS_LPCR);
- timeout = jiffies + msecs_to_jiffies(3000);
- while (!(readl(ioaddr + SNVS_LPCR) & SNVS_LPCR_SRTC_ENV)) {
if (time_after(jiffies, timeout)) {dev_err(dev, "timeout on enabling RTC back\n");return -EBUSY;}- }
- rtc_write_sync_lp(ioaddr);
- new_time_47bit = (((u64) (readl(ioaddr + SNVS_LPSRTCMR) &
((0x1 << CNTR_TO_SECS_SH) - 1)) << 32) |((u64) readl(ioaddr + SNVS_LPSRTCLR)));- time_diff = new_time_47bit - old_time_47bit;
time_diff, old_time_47bit and new_time_47bit are set and never read. Remove.
- return 0;
+}
+static int snvs_rtc_proc(struct device *dev, struct seq_file *seq) +{
- struct rtc_drv_data *pdata = dev_get_drvdata(dev);
- void __iomem *ioaddr = pdata->ioaddr;
- seq_printf(seq, "alarm_IRQ\t: %s\n",
(((readl(ioaddr + SNVS_LPCR)) & SNVS_LPCR_LPTA_EN) !=0) ? "yes" : "no");- return 0;
+}
+static int snvs_rtc_alarm_irq_enable(struct device *dev, unsigned int enable) +{
- struct rtc_drv_data *pdata = dev_get_drvdata(dev);
- void __iomem *ioaddr = pdata->ioaddr;
- u32 lp_cr;
- unsigned long lock_flags = 0;
- spin_lock_irqsave(&rtc_lock, lock_flags);
- if (enable) {
if (!pdata->irq_enable) {enable_irq(pdata->irq);pdata->irq_enable = true;}
Why this enable_irq/disable_irq everywhere? You seem to have irq enable bits in your registers which should be enough.
+/* SNVS RTC Power management control */ +static int __devinit snvs_rtc_probe(struct platform_device *pdev) +{
- struct timespec tv;
- struct rtc_device *rtc;
- struct rtc_drv_data *pdata = NULL;
No need to initialize this. I think you should use another name for this variable. People usually expect pdata for platform_data. Driver data is usually called priv, or snvs_rtc in this case.
- void __iomem *ioaddr;
- u32 lp_cr;
- int ret = 0;
No need to initialize this.
- ioaddr = of_iomap(pdev->dev.of_node, 0);
- if (!ioaddr)
return -EADDRNOTAVAIL;- pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
- if (!pdata)
return -ENOMEM;- pdata->ioaddr = ioaddr;
- /* Configure and enable the RTC */
- pdata->irq = platform_get_irq(pdev, 0);
- if (pdata->irq >= 0) {
Is there any hardware without an interrupt? If no, just bail out here and get rid of the additional complexity.
if (request_irq(pdata->irq, snvs_rtc_interrupt, IRQF_SHARED,pdev->name, pdev) < 0) {dev_warn(&pdev->dev, "interrupt not available.\n");pdata->irq = -1;} else {disable_irq(pdata->irq);pdata->irq_enable = false;}- }
- /* initialize glitch detect */
- writel(SNVS_LPPGDR_INIT, ioaddr + SNVS_LPPGDR);
- udelay(100);
- /* clear lp interrupt status */
- writel(0xFFFFFFFF, ioaddr + SNVS_LPSR);
- /* Enable RTC */
- lp_cr = readl(ioaddr + SNVS_LPCR);
- if ((lp_cr & SNVS_LPCR_SRTC_ENV) == 0)
writel(lp_cr | SNVS_LPCR_SRTC_ENV, ioaddr + SNVS_LPCR);- udelay(100);
- writel(0xFFFFFFFF, ioaddr + SNVS_LPSR);
- udelay(100);
- platform_set_drvdata(pdev, pdata);
- rtc = rtc_device_register(pdev->name, &pdev->dev,
&snvs_rtc_ops, THIS_MODULE);- if (IS_ERR(rtc)) {
ret = PTR_ERR(rtc);goto err_out;- }
- pdata->rtc = rtc;
- tv.tv_nsec = 0;
- tv.tv_sec = rtc_read_lp_counter(ioaddr);
- /* By default, devices should wakeup if they can */
- /* So snvs is set as "should wakeup" as it can */
- device_init_wakeup(&pdev->dev, 1);
- return ret;
return 0 here instead to make it clear that this is the success path.
+err_out:
- iounmap(ioaddr);
- if (pdata->irq >= 0)
free_irq(pdata->irq, pdev);- return ret;
+}
+static int __devexit snvs_rtc_remove(struct platform_device *pdev) +{
- struct rtc_drv_data *pdata = platform_get_drvdata(pdev);
- rtc_device_unregister(pdata->rtc);
- if (pdata->irq >= 0)
free_irq(pdata->irq, pdev);- iounmap(pdata->ioaddr);
- return 0;
+}