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Subject[PATCH] clocksource: sh_cmt: 32-bit control register support
From: Magnus Damm <damm@opensource.se>

Add support for CMT hardware with 32-bit control and counter
registers, as found on r8a73a4 and r8a7790. To use the CMT
with 32-bit hardware a second I/O memory resource needs to
point out the CMSTR register and it needs to be 32 bit wide.

Signed-off-by: Magnus Damm <damm@opensource.se>
---

Tested on r8a73a4 used on APE6EVM.

drivers/clocksource/sh_cmt.c | 50 ++++++++++++++++++++++++++++++------------
1 file changed, 36 insertions(+), 14 deletions(-)

--- 0001/drivers/clocksource/sh_cmt.c
+++ work/drivers/clocksource/sh_cmt.c 2013-06-17 13:47:34.000000000 +0900
@@ -37,6 +37,7 @@

struct sh_cmt_priv {
void __iomem *mapbase;
+ void __iomem *mapbase_str;
struct clk *clk;
unsigned long width; /* 16 or 32 bit version of hardware block */
unsigned long overflow_bit;
@@ -79,6 +80,12 @@ struct sh_cmt_priv {
* CMCSR 0xffca0060 16-bit
* CMCNT 0xffca0064 32-bit
* CMCOR 0xffca0068 32-bit
+ *
+ * "32-bit counter and 32-bit control" as found on r8a73a4 and r8a7790:
+ * CMSTR 0xffca0500 32-bit
+ * CMCSR 0xffca0510 32-bit
+ * CMCNT 0xffca0514 32-bit
+ * CMCOR 0xffca0518 32-bit
*/

static unsigned long sh_cmt_read16(void __iomem *base, unsigned long offs)
@@ -109,9 +116,7 @@ static void sh_cmt_write32(void __iomem

static inline unsigned long sh_cmt_read_cmstr(struct sh_cmt_priv *p)
{
- struct sh_timer_config *cfg = p->pdev->dev.platform_data;
-
- return p->read_control(p->mapbase - cfg->channel_offset, 0);
+ return p->read_control(p->mapbase_str, 0);
}

static inline unsigned long sh_cmt_read_cmcsr(struct sh_cmt_priv *p)
@@ -127,9 +132,7 @@ static inline unsigned long sh_cmt_read_
static inline void sh_cmt_write_cmstr(struct sh_cmt_priv *p,
unsigned long value)
{
- struct sh_timer_config *cfg = p->pdev->dev.platform_data;
-
- p->write_control(p->mapbase - cfg->channel_offset, 0, value);
+ p->write_control(p->mapbase_str, 0, value);
}

static inline void sh_cmt_write_cmcsr(struct sh_cmt_priv *p,
@@ -676,7 +679,7 @@ static int sh_cmt_register(struct sh_cmt
static int sh_cmt_setup(struct sh_cmt_priv *p, struct platform_device *pdev)
{
struct sh_timer_config *cfg = pdev->dev.platform_data;
- struct resource *res;
+ struct resource *res, *res2;
int irq, ret;
ret = -ENXIO;

@@ -694,6 +697,9 @@ static int sh_cmt_setup(struct sh_cmt_pr
goto err0;
}

+ /* optional resource for the shared timer start/stop register */
+ res2 = platform_get_resource(p->pdev, IORESOURCE_MEM, 1);
+
irq = platform_get_irq(p->pdev, 0);
if (irq < 0) {
dev_err(&p->pdev->dev, "failed to get irq\n");
@@ -707,6 +713,15 @@ static int sh_cmt_setup(struct sh_cmt_pr
goto err0;
}

+ /* map second resource for CMSTR */
+ p->mapbase_str = ioremap_nocache(res2 ? res2->start :
+ res->start - cfg->channel_offset,
+ res2 ? resource_size(res2) : 2);
+ if (p->mapbase_str == NULL) {
+ dev_err(&p->pdev->dev, "failed to remap I/O second memory\n");
+ goto err1;
+ }
+
/* request irq using setup_irq() (too early for request_irq()) */
p->irqaction.name = dev_name(&p->pdev->dev);
p->irqaction.handler = sh_cmt_interrupt;
@@ -719,11 +734,17 @@ static int sh_cmt_setup(struct sh_cmt_pr
if (IS_ERR(p->clk)) {
dev_err(&p->pdev->dev, "cannot get clock\n");
ret = PTR_ERR(p->clk);
- goto err1;
+ goto err2;
}

- p->read_control = sh_cmt_read16;
- p->write_control = sh_cmt_write16;
+ if (res2 && (resource_size(res2) == 4)) {
+ /* assume both CMSTR and CMCSR to be 32-bit */
+ p->read_control = sh_cmt_read32;
+ p->write_control = sh_cmt_write32;
+ } else {
+ p->read_control = sh_cmt_read16;
+ p->write_control = sh_cmt_write16;
+ }

if (resource_size(res) == 6) {
p->width = 16;
@@ -752,22 +773,23 @@ static int sh_cmt_setup(struct sh_cmt_pr
cfg->clocksource_rating);
if (ret) {
dev_err(&p->pdev->dev, "registration failed\n");
- goto err2;
+ goto err3;
}
p->cs_enabled = false;

ret = setup_irq(irq, &p->irqaction);
if (ret) {
dev_err(&p->pdev->dev, "failed to request irq %d\n", irq);
- goto err2;
+ goto err3;
}

platform_set_drvdata(pdev, p);

return 0;
-err2:
+err3:
clk_put(p->clk);
-
+err2:
+ iounmap(p->mapbase_str);
err1:
iounmap(p->mapbase);
err0:

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