[linux-keystone] Re: [PATCH] arm:davinci: clk - migrate to new common clock API

quoted

-----Original Message-----
From: Turquette, Mike
Sent: Thursday, August 02, 2012 5:20 PM
To: Karicheri, Muralidharan
Cc: linux-arm-kernel at lists.infradead.org; davinci-linux-open-
source at linux.davincidsp.com; linux-keystone at list.ti.com - Linux developers for Keystone
family of devices (May contain non-TIers); Chemparathy, Cyril; Nori, Sekhar;
linux at arm.linux.org.uk
Subject: [linux-keystone] Re: [PATCH] arm:davinci: clk - migrate to new common clock
API

On 20120802-12:53, Murali Karicheri wrote:

quoted

As a first step towards migrating davinci platforms to use common clock
framework, replace all instances of clk_enable() with clk_prepare_enable()
and clk_disable() with clk_disable_unprepare(). Until the platform is
switched to use the CONFIG_HAVE_CLK_PREPARE Kconfig variable, this just
adds a might_sleep() call and would work without any issues.

This will make it easy later to switch to common clk based implementation
of clk driver from DaVinci specific driver.

Signed-off-by: Murali Karicheri <redacted>

Murali,

The important thing to know about clk_prepare is that it might sleep.
All of the functions below look like initialization functions for code
that is never run in interrupt context.  If you can confirm that this is
true then feel free to add my,

Mike,

I believe they are. I will double check and then post the patch again. If they are called under
interrupt context, basically I need to make two API calls instead as below right?

clk_prepare()
clk_enable()

Murali Karicheri
Software Design Engineer

quoted

Reviewed-by: Mike Turquette <redacted>

Regards,
Mike

quoted

---
 arch/arm/mach-davinci/board-dm355-evm.c     |    2 +-
 arch/arm/mach-davinci/board-dm355-leopard.c |    2 +-
 arch/arm/mach-davinci/board-dm365-evm.c     |    4 ++--
 arch/arm/mach-davinci/board-dm644x-evm.c    |    2 +-
 arch/arm/mach-davinci/board-neuros-osd2.c   |    2 +-
 arch/arm/mach-davinci/devices-da8xx.c       |    6 +++---
 arch/arm/mach-davinci/serial.c              |    2 +-
 arch/arm/mach-davinci/time.c                |    4 ++--
 8 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/arch/arm/mach-davinci/board-dm355-evm.c b/arch/arm/mach-

davinci/board-dm355-evm.c

quoted

index 1c7b1f4..4821fba 100644

--- a/arch/arm/mach-davinci/board-dm355-evm.c
+++ b/arch/arm/mach-davinci/board-dm355-evm.c

@@ -324,7 +324,7 @@ static __init void dm355_evm_init(void)
 	if (IS_ERR(aemif))
 		WARN("%s: unable to get AEMIF clock\n", __func__);
 	else
-		clk_enable(aemif);
+		clk_prepare_enable(aemif);

 	platform_add_devices(davinci_evm_devices,
 			     ARRAY_SIZE(davinci_evm_devices));

diff --git a/arch/arm/mach-davinci/board-dm355-leopard.c b/arch/arm/mach-

davinci/board-dm355-leopard.c

quoted

index 8e77032..b754ccf 100644

--- a/arch/arm/mach-davinci/board-dm355-leopard.c
+++ b/arch/arm/mach-davinci/board-dm355-leopard.c

@@ -246,7 +246,7 @@ static __init void dm355_leopard_init(void)
 	if (IS_ERR(aemif))
 		WARN("%s: unable to get AEMIF clock\n", __func__);
 	else
-		clk_enable(aemif);
+		clk_prepare_enable(aemif);

 	platform_add_devices(davinci_leopard_devices,
 			     ARRAY_SIZE(davinci_leopard_devices));

diff --git a/arch/arm/mach-davinci/board-dm365-evm.c b/arch/arm/mach-

davinci/board-dm365-evm.c

quoted

index 2830692..3a4743b 100644

--- a/arch/arm/mach-davinci/board-dm365-evm.c
+++ b/arch/arm/mach-davinci/board-dm365-evm.c

@@ -481,7 +481,7 @@ static void __init evm_init_cpld(void)
 	aemif_clk = clk_get(NULL, "aemif");
 	if (IS_ERR(aemif_clk))
 		return;
-	clk_enable(aemif_clk);
+	clk_prepare_enable(aemif_clk);

 	if (request_mem_region(DM365_ASYNC_EMIF_DATA_CE1_BASE, SECTION_SIZE,
 			"cpld") == NULL)

@@ -492,7 +492,7 @@ static void __init evm_init_cpld(void)
 				SECTION_SIZE);
 fail:
 		pr_err("ERROR: can't map CPLD\n");
-		clk_disable(aemif_clk);
+		clk_disable_unprepare(aemif_clk);
 		return;
 	}

diff --git a/arch/arm/mach-davinci/board-dm644x-evm.c b/arch/arm/mach-

davinci/board-dm644x-evm.c

quoted

index d34ed55..04ef708 100644

--- a/arch/arm/mach-davinci/board-dm644x-evm.c
+++ b/arch/arm/mach-davinci/board-dm644x-evm.c

@@ -775,7 +775,7 @@ static __init void davinci_evm_init(void)
 	struct davinci_soc_info *soc_info = &davinci_soc_info;

 	aemif_clk = clk_get(NULL, "aemif");
-	clk_enable(aemif_clk);
+	clk_prepare_enable(aemif_clk);

 	if (HAS_ATA) {
 		if (HAS_NAND || HAS_NOR)

diff --git a/arch/arm/mach-davinci/board-neuros-osd2.c b/arch/arm/mach-

davinci/board-neuros-osd2.c

quoted

index 5de69f2..7fdd0a7b 100644

--- a/arch/arm/mach-davinci/board-neuros-osd2.c
+++ b/arch/arm/mach-davinci/board-neuros-osd2.c

@@ -221,7 +221,7 @@ static __init void davinci_ntosd2_init(void)
 	int	status;

 	aemif_clk = clk_get(NULL, "aemif");
-	clk_enable(aemif_clk);
+	clk_prepare_enable(aemif_clk);

 	if (HAS_ATA) {
 		if (HAS_NAND)

diff --git a/arch/arm/mach-davinci/devices-da8xx.c b/arch/arm/mach-davinci/devices-

da8xx.c

quoted

index d1624a3..20141f5 100644

--- a/arch/arm/mach-davinci/devices-da8xx.c
+++ b/arch/arm/mach-davinci/devices-da8xx.c

@@ -905,7 +905,7 @@ static int da850_sata_init(struct device *dev, void __iomem

*addr)

quoted

 	if (IS_ERR(da850_sata_clk))
 		return PTR_ERR(da850_sata_clk);

-	ret = clk_enable(da850_sata_clk);
+	ret = clk_prepare_enable(da850_sata_clk);
 	if (ret)
 		goto err0;

@@ -936,7 +936,7 @@ static int da850_sata_init(struct device *dev, void __iomem

*addr)

quoted

 	return 0;

 err1:
-	clk_disable(da850_sata_clk);
+	clk_disable_unprepare(da850_sata_clk);
 err0:
 	clk_put(da850_sata_clk);
 	return ret;

@@ -944,7 +944,7 @@ err0:

 static void da850_sata_exit(struct device *dev)
 {
-	clk_disable(da850_sata_clk);
+	clk_disable_unprepare(da850_sata_clk);
 	clk_put(da850_sata_clk);
 }

diff --git a/arch/arm/mach-davinci/serial.c b/arch/arm/mach-davinci/serial.c
index 1875740..24ddb0d 100644
--- a/arch/arm/mach-davinci/serial.c
+++ b/arch/arm/mach-davinci/serial.c

@@ -95,7 +95,7 @@ int __init davinci_serial_init(struct davinci_uart_config *info)
 			continue;
 		}

-		clk_enable(uart_clk);
+		clk_prepare_enable(uart_clk);
 		p->uartclk = clk_get_rate(uart_clk);

 		if (!p->membase && p->mapbase) {

diff --git a/arch/arm/mach-davinci/time.c b/arch/arm/mach-davinci/time.c
index 75da315..9847938 100644
--- a/arch/arm/mach-davinci/time.c
+++ b/arch/arm/mach-davinci/time.c

@@ -379,7 +379,7 @@ static void __init davinci_timer_init(void)

 	timer_clk = clk_get(NULL, "timer0");
 	BUG_ON(IS_ERR(timer_clk));
-	clk_enable(timer_clk);
+	clk_prepare_enable(timer_clk);

 	/* init timer hw */
 	timer_init();

@@ -429,7 +429,7 @@ void davinci_watchdog_reset(struct platform_device *pdev)
 	wd_clk = clk_get(&pdev->dev, NULL);
 	if (WARN_ON(IS_ERR(wd_clk)))
 		return;
-	clk_enable(wd_clk);
+	clk_prepare_enable(wd_clk);

 	/* disable, internal clock source */
 	__raw_writel(0, base + TCR);
--

1.7.9.5