[PATCH v4 1/6] rtc: arm: imx: snvs: change use syscon to access register
Shawn Guo
shawn.guo at linaro.org
Sun May 24 23:18:04 PDT 2015
On Fri, May 22, 2015 at 10:36:34PM +0800, Frank.Li at freescale.com wrote:
> From: Frank Li <Frank.Li at freescale.com>
>
> snvs included rtc, on/off key, power-off module
> change to syscon to access register
>
> Signed-off-by: Frank Li <Frank.Li at freescale.com>
Did you test it with both existing and new DTBs?
> ---
> drivers/rtc/rtc-snvs.c | 136 +++++++++++++++++++++++++------------------------
> 1 file changed, 70 insertions(+), 66 deletions(-)
>
> diff --git a/drivers/rtc/rtc-snvs.c b/drivers/rtc/rtc-snvs.c
> index 0479e80..42e55da 100644
> --- a/drivers/rtc/rtc-snvs.c
> +++ b/drivers/rtc/rtc-snvs.c
> @@ -18,6 +18,8 @@
> #include <linux/platform_device.h>
> #include <linux/rtc.h>
> #include <linux/clk.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/regmap.h>
>
> /* These register offsets are relative to LP (Low Power) range */
> #define SNVS_LPCR 0x04
> @@ -37,31 +39,35 @@
>
> struct snvs_rtc_data {
> struct rtc_device *rtc;
> - void __iomem *ioaddr;
> + struct regmap *regmap;
> + int offset;
> int irq;
> - spinlock_t lock;
> struct clk *clk;
> };
>
> -static u32 rtc_read_lp_counter(void __iomem *ioaddr)
> +static u32 rtc_read_lp_counter(struct snvs_rtc_data *snvs)
All the pointers to struct snvs_rtc_data are named 'data'. Please keep
it consistent.
> {
> u64 read1, read2;
> -
> + u32 val;
Please keep the new line here.
> do {
> - read1 = readl(ioaddr + SNVS_LPSRTCMR);
> + regmap_read(snvs->regmap, snvs->offset + SNVS_LPSRTCMR, &val);
> + read1 = val;
> read1 <<= 32;
> - read1 |= readl(ioaddr + SNVS_LPSRTCLR);
> + regmap_read(snvs->regmap, snvs->offset + SNVS_LPSRTCLR, &val);
> + read1 |= val;
>
> - read2 = readl(ioaddr + SNVS_LPSRTCMR);
> + regmap_read(snvs->regmap, snvs->offset + SNVS_LPSRTCMR, &val);
> + read2 = val;
> read2 <<= 32;
> - read2 |= readl(ioaddr + SNVS_LPSRTCLR);
> + regmap_read(snvs->regmap, snvs->offset + SNVS_LPSRTCLR, &val);
> + read2 |= val;
> } while (read1 != read2);
>
> /* Convert 47-bit counter to 32-bit raw second count */
> return (u32) (read1 >> CNTR_TO_SECS_SH);
> }
>
> -static void rtc_write_sync_lp(void __iomem *ioaddr)
> +static void rtc_write_sync_lp(struct snvs_rtc_data *snvs)
> {
> u32 count1, count2, count3;
> int i;
> @@ -69,15 +75,15 @@ static void rtc_write_sync_lp(void __iomem *ioaddr)
> /* Wait for 3 CKIL cycles */
> for (i = 0; i < 3; i++) {
> do {
> - count1 = readl(ioaddr + SNVS_LPSRTCLR);
> - count2 = readl(ioaddr + SNVS_LPSRTCLR);
> + regmap_read(snvs->regmap, snvs->offset + SNVS_LPSRTCLR, &count1);
> + regmap_read(snvs->regmap, snvs->offset + SNVS_LPSRTCLR, &count2);
> } while (count1 != count2);
>
> /* Now wait until counter value changes */
> do {
> do {
> - count2 = readl(ioaddr + SNVS_LPSRTCLR);
> - count3 = readl(ioaddr + SNVS_LPSRTCLR);
> + regmap_read(snvs->regmap, snvs->offset + SNVS_LPSRTCLR, &count2);
> + regmap_read(snvs->regmap, snvs->offset + SNVS_LPSRTCLR, &count3);
> } while (count2 != count3);
> } while (count3 == count1);
> }
> @@ -85,23 +91,14 @@ static void rtc_write_sync_lp(void __iomem *ioaddr)
>
> static int snvs_rtc_enable(struct snvs_rtc_data *data, bool enable)
> {
> - unsigned long flags;
> int timeout = 1000;
> u32 lpcr;
>
> - spin_lock_irqsave(&data->lock, flags);
> -
> - lpcr = readl(data->ioaddr + SNVS_LPCR);
> - if (enable)
> - lpcr |= SNVS_LPCR_SRTC_ENV;
> - else
> - lpcr &= ~SNVS_LPCR_SRTC_ENV;
> - writel(lpcr, data->ioaddr + SNVS_LPCR);
> -
> - spin_unlock_irqrestore(&data->lock, flags);
> + regmap_update_bits(data->regmap, data->offset + SNVS_LPCR, SNVS_LPCR_SRTC_ENV,
> + enable ? SNVS_LPCR_SRTC_ENV : 0);
>
> while (--timeout) {
> - lpcr = readl(data->ioaddr + SNVS_LPCR);
> + regmap_read(data->regmap, data->offset + SNVS_LPCR, &lpcr);
>
> if (enable) {
> if (lpcr & SNVS_LPCR_SRTC_ENV)
> @@ -121,7 +118,7 @@ static int snvs_rtc_enable(struct snvs_rtc_data *data, bool enable)
> static int snvs_rtc_read_time(struct device *dev, struct rtc_time *tm)
> {
> struct snvs_rtc_data *data = dev_get_drvdata(dev);
> - unsigned long time = rtc_read_lp_counter(data->ioaddr);
> + unsigned long time = rtc_read_lp_counter(data);
>
> rtc_time_to_tm(time, tm);
>
> @@ -139,8 +136,8 @@ static int snvs_rtc_set_time(struct device *dev, struct rtc_time *tm)
> snvs_rtc_enable(data, false);
>
> /* Write 32-bit time to 47-bit timer, leaving 15 LSBs blank */
> - writel(time << CNTR_TO_SECS_SH, data->ioaddr + SNVS_LPSRTCLR);
> - writel(time >> (32 - CNTR_TO_SECS_SH), data->ioaddr + SNVS_LPSRTCMR);
> + regmap_write(data->regmap, data->offset + SNVS_LPSRTCLR, time << CNTR_TO_SECS_SH);
> + regmap_write(data->regmap, data->offset + SNVS_LPSRTCMR, time >> (32 - CNTR_TO_SECS_SH));
>
> /* Enable RTC again */
> snvs_rtc_enable(data, true);
> @@ -153,10 +150,10 @@ static int snvs_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
> struct snvs_rtc_data *data = dev_get_drvdata(dev);
> u32 lptar, lpsr;
>
> - lptar = readl(data->ioaddr + SNVS_LPTAR);
> + regmap_read(data->regmap, data->offset + SNVS_LPTAR, &lptar);
> rtc_time_to_tm(lptar, &alrm->time);
>
> - lpsr = readl(data->ioaddr + SNVS_LPSR);
> + regmap_read(data->regmap, data->offset + SNVS_LPSR, &lpsr);
> alrm->pending = (lpsr & SNVS_LPSR_LPTA) ? 1 : 0;
>
> return 0;
> @@ -165,21 +162,12 @@ static int snvs_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
> static int snvs_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
> {
> struct snvs_rtc_data *data = dev_get_drvdata(dev);
> - u32 lpcr;
> - unsigned long flags;
> -
> - spin_lock_irqsave(&data->lock, flags);
> -
> - lpcr = readl(data->ioaddr + SNVS_LPCR);
> - if (enable)
> - lpcr |= (SNVS_LPCR_LPTA_EN | SNVS_LPCR_LPWUI_EN);
> - else
> - lpcr &= ~(SNVS_LPCR_LPTA_EN | SNVS_LPCR_LPWUI_EN);
> - writel(lpcr, data->ioaddr + SNVS_LPCR);
>
> - spin_unlock_irqrestore(&data->lock, flags);
> + regmap_update_bits(data->regmap, data->offset + SNVS_LPCR,
> + (SNVS_LPCR_LPTA_EN | SNVS_LPCR_LPWUI_EN),
> + enable ? (SNVS_LPCR_LPTA_EN | SNVS_LPCR_LPWUI_EN) : 0);
>
> - rtc_write_sync_lp(data->ioaddr);
> + rtc_write_sync_lp(data);
>
> return 0;
> }
> @@ -189,24 +177,14 @@ static int snvs_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
> struct snvs_rtc_data *data = dev_get_drvdata(dev);
> struct rtc_time *alrm_tm = &alrm->time;
> unsigned long time;
> - unsigned long flags;
> - u32 lpcr;
>
> rtc_tm_to_time(alrm_tm, &time);
>
> - spin_lock_irqsave(&data->lock, flags);
> -
> - /* Have to clear LPTA_EN before programming new alarm time in LPTAR */
> - lpcr = readl(data->ioaddr + SNVS_LPCR);
> - lpcr &= ~SNVS_LPCR_LPTA_EN;
> - writel(lpcr, data->ioaddr + SNVS_LPCR);
> -
> - spin_unlock_irqrestore(&data->lock, flags);
> -
> - writel(time, data->ioaddr + SNVS_LPTAR);
> + regmap_update_bits(data->regmap, data->offset + SNVS_LPCR, SNVS_LPCR_LPTA_EN, 0);
> + regmap_write(data->regmap, data->offset + SNVS_LPTAR, time);
>
> /* Clear alarm interrupt status bit */
> - writel(SNVS_LPSR_LPTA, data->ioaddr + SNVS_LPSR);
> + regmap_write(data->regmap, data->offset + SNVS_LPSR, SNVS_LPSR_LPTA);
>
> return snvs_rtc_alarm_irq_enable(dev, alrm->enabled);
> }
> @@ -226,7 +204,7 @@ static irqreturn_t snvs_rtc_irq_handler(int irq, void *dev_id)
> u32 lpsr;
> u32 events = 0;
>
> - lpsr = readl(data->ioaddr + SNVS_LPSR);
> + regmap_read(data->regmap, data->offset + SNVS_LPSR, &lpsr);
>
> if (lpsr & SNVS_LPSR_LPTA) {
> events |= (RTC_AF | RTC_IRQF);
> @@ -238,25 +216,53 @@ static irqreturn_t snvs_rtc_irq_handler(int irq, void *dev_id)
> }
>
> /* clear interrupt status */
> - writel(lpsr, data->ioaddr + SNVS_LPSR);
> + regmap_write(data->regmap, data->offset + SNVS_LPSR, lpsr);
>
> return events ? IRQ_HANDLED : IRQ_NONE;
> }
>
> +static const struct regmap_config snvs_rtc_config = {
> + .reg_bits = 32,
> + .val_bits = 32,
> + .reg_stride = 4,
> +};
> +
> static int snvs_rtc_probe(struct platform_device *pdev)
> {
> struct snvs_rtc_data *data;
> struct resource *res;
> int ret;
> + struct device_node *snvs_np;
Since you have only one pointer to device_node in this function, name
'np' is probably just fine.
> + void __iomem *mmio;
>
> data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> if (!data)
> return -ENOMEM;
>
> - res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> - data->ioaddr = devm_ioremap_resource(&pdev->dev, res);
> - if (IS_ERR(data->ioaddr))
> - return PTR_ERR(data->ioaddr);
> + snvs_np = of_get_parent(pdev->dev.of_node);
> + if (!snvs_np)
> + return -ENODEV;
> +
> + if (of_device_is_compatible(snvs_np, "syscon")) {
> + data->regmap = syscon_node_to_regmap(snvs_np);
> + data->offset = 0x34;
You should at least have a macro for this magic number to tell what it
is?
> + } else {
> + pr_warn("snvs rtc: you use old dts file, please update it\n");
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +
> + mmio = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(mmio))
> + return PTR_ERR(mmio);
So if it fails out from here, of_node_put() call will be skipped.
> +
> + data->regmap = devm_regmap_init_mmio(&pdev->dev, mmio, &snvs_rtc_config);
> + }
> +
> + of_node_put(snvs_np);
> +
> + if (!data->regmap) {
> + pr_err("Can't snvs syscon\n");
dev_err(), and "Can't find" or something?
Shawn
> + return -ENODEV;
> + }
>
> data->irq = platform_get_irq(pdev, 0);
> if (data->irq < 0)
> @@ -276,13 +282,11 @@ static int snvs_rtc_probe(struct platform_device *pdev)
>
> platform_set_drvdata(pdev, data);
>
> - spin_lock_init(&data->lock);
> -
> /* Initialize glitch detect */
> - writel(SNVS_LPPGDR_INIT, data->ioaddr + SNVS_LPPGDR);
> + regmap_write(data->regmap, data->offset + SNVS_LPPGDR, SNVS_LPPGDR_INIT);
>
> /* Clear interrupt status */
> - writel(0xffffffff, data->ioaddr + SNVS_LPSR);
> + regmap_write(data->regmap, data->offset + SNVS_LPSR, 0xffffffff);
>
> /* Enable RTC */
> snvs_rtc_enable(data, true);
> --
> 1.9.1
>
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