Skip to content

Commit

Permalink
rtc: snvs: use syscon to access register
Browse files Browse the repository at this point in the history 
snvs included rtc, on/off key, power-off module
change to syscon to access register

Signed-off-by: Frank Li <Frank.Li@freescale.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
  • Loading branch information
Frank Li authored and Shawn Guo committed Jul 15, 2015
1 parent 20c305f commit d482893
Showing 1 changed file with 67 additions and 65 deletions.
132 changes: 67 additions & 65 deletions drivers/rtc/rtc-snvs.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -18,6 +18,10 @@
#include <linux/platform_device.h>
#include <linux/rtc.h>
#include <linux/clk.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>

#define SNVS_LPREGISTER_OFFSET 0x34

/* These register offsets are relative to LP (Low Power) range */
#define SNVS_LPCR 0x04
Expand All @@ -37,71 +41,67 @@

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 *data)
{
u64 read1, read2;
u32 val;

do {
read1 = readl(ioaddr + SNVS_LPSRTCMR);
regmap_read(data->regmap, data->offset + SNVS_LPSRTCMR, &val);
read1 = val;
read1 <<= 32;
read1 |= readl(ioaddr + SNVS_LPSRTCLR);
regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &val);
read1 |= val;

read2 = readl(ioaddr + SNVS_LPSRTCMR);
regmap_read(data->regmap, data->offset + SNVS_LPSRTCMR, &val);
read2 = val;
read2 <<= 32;
read2 |= readl(ioaddr + SNVS_LPSRTCLR);
regmap_read(data->regmap, data->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 *data)
{
u32 count1, count2, count3;
int i;

/* Wait for 3 CKIL cycles */
for (i = 0; i < 3; i++) {
do {
count1 = readl(ioaddr + SNVS_LPSRTCLR);
count2 = readl(ioaddr + SNVS_LPSRTCLR);
regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &count1);
regmap_read(data->regmap, data->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(data->regmap, data->offset + SNVS_LPSRTCLR, &count2);
regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &count3);
} while (count2 != count3);
} while (count3 == count1);
}
}

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)
Expand All @@ -121,7 +121,7 @@ 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);

Expand All @@ -139,8 +139,8 @@ 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);
Expand All @@ -153,10 +153,10 @@ 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;
Expand All @@ -165,21 +165,12 @@ 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);
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);

spin_unlock_irqrestore(&data->lock, flags);

rtc_write_sync_lp(data->ioaddr);
rtc_write_sync_lp(data);

return 0;
}
Expand All @@ -189,24 +180,14 @@ 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);
}
Expand All @@ -226,7 +207,7 @@ 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);
Expand All @@ -238,25 +219,48 @@ 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;
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);
data->regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "regmap");

if (IS_ERR(data->regmap)) {
dev_warn(&pdev->dev, "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);

data->regmap = devm_regmap_init_mmio(&pdev->dev, mmio, &snvs_rtc_config);
} else {
data->offset = SNVS_LPREGISTER_OFFSET;
of_property_read_u32(pdev->dev.of_node, "offset", &data->offset);
}

if (!data->regmap) {
dev_err(&pdev->dev, "Can't find snvs syscon\n");
return -ENODEV;
}

data->irq = platform_get_irq(pdev, 0);
if (data->irq < 0)
Expand All @@ -276,13 +280,11 @@ 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);
Expand Down

0 comments on commit d482893

Please sign in to comment.