diff mbox series

[v3,03/13] spi: atmel-quadspi: drop wrappers for iomem accesses

Message ID 20190202040653.1217-4-tudor.ambarus@microchip.com (mailing list archive)
State Superseded
Headers show
Series spi: atmel-quadspi: introduce sam9x60 qspi controller | expand

Commit Message

Tudor Ambarus Feb. 2, 2019, 4:07 a.m. UTC 
From: Tudor Ambarus <tudor.ambarus@microchip.com>

The wrappers hid that the accesses are relaxed. Drop them.

Suggested-by: Boris Brezillon <bbrezillon@kernel.org>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
---
v3: no change
v2: new patch

 drivers/spi/atmel-quadspi.c | 47 +++++++++++++++++++--------------------------
 1 file changed, 20 insertions(+), 27 deletions(-)

Comments

Boris Brezillon Feb. 2, 2019, 7:11 a.m. UTC | #1 
On Sat, 2 Feb 2019 04:07:19 +0000
<Tudor.Ambarus@microchip.com> wrote:

> From: Tudor Ambarus <tudor.ambarus@microchip.com>
> 
> The wrappers hid that the accesses are relaxed. Drop them.
> 
> Suggested-by: Boris Brezillon <bbrezillon@kernel.org>
> Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
> ---
> v3: no change
> v2: new patch
> 
>  drivers/spi/atmel-quadspi.c | 47 +++++++++++++++++++--------------------------
>  1 file changed, 20 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/spi/atmel-quadspi.c b/drivers/spi/atmel-quadspi.c
> index feeddcb25e1f..131374db0db4 100644
> --- a/drivers/spi/atmel-quadspi.c
> +++ b/drivers/spi/atmel-quadspi.c
> @@ -175,17 +175,6 @@ static const struct qspi_mode sama5d2_qspi_modes[] = {
>  	{ 4, 4, 4, QSPI_IFR_WIDTH_QUAD_CMD },
>  };
>  
> -/* Register access functions */
> -static inline u32 qspi_readl(struct atmel_qspi *aq, u32 reg)
> -{
> -	return readl_relaxed(aq->regs + reg);
> -}
> -
> -static inline void qspi_writel(struct atmel_qspi *aq, u32 reg, u32 value)
> -{
> -	writel_relaxed(value, aq->regs + reg);
> -}
> -
>  static inline bool is_compatible(const struct spi_mem_op *op,
>  				 const struct qspi_mode *mode)
>  {
> @@ -229,6 +218,7 @@ static bool atmel_qspi_supports_op(struct spi_mem *mem,
>  static int atmel_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
>  {
>  	struct atmel_qspi *aq = spi_controller_get_devdata(mem->spi->master);
> +	void __iomem *base = aq->regs;

Can we name this variable regs instead of base or even get rid of it
and dereference aq->regs in the xxx_relaxed() calls (doesn't look like
the lines would be over 80 chars even when doing that). With this
addressed, you can add:

Reviewed-by: Boris Brezillon <bbrezillon@kernel.org>

>  	int mode;
>  	u32 dummy_cycles = 0;
>  	u32 iar, icr, ifr, sr;
> @@ -240,7 +230,7 @@ static int atmel_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
>  
>  	/* Set the QSPI controller in Serial Memory Mode */
>  	if (aq->smm != QSPI_MR_SMM) {
> -		qspi_writel(aq, QSPI_MR, QSPI_MR_SMM);
> +		writel_relaxed(QSPI_MR_SMM, base + QSPI_MR);
>  		aq->smm = QSPI_MR_SMM;
>  	}
>  
> @@ -300,17 +290,17 @@ static int atmel_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
>  		ifr |= QSPI_IFR_TFRTYP_TRSFR_WRITE;
>  
>  	/* Clear pending interrupts */
> -	(void)qspi_readl(aq, QSPI_SR);
> +	(void)readl_relaxed(base + QSPI_SR);
>  
>  	/* Set QSPI Instruction Frame registers */
> -	qspi_writel(aq, QSPI_IAR, iar);
> -	qspi_writel(aq, QSPI_ICR, icr);
> -	qspi_writel(aq, QSPI_IFR, ifr);
> +	writel_relaxed(iar, base + QSPI_IAR);
> +	writel_relaxed(icr, base + QSPI_ICR);
> +	writel_relaxed(ifr, base + QSPI_IFR);
>  
>  	/* Skip to the final steps if there is no data */
>  	if (op->data.nbytes) {
>  		/* Dummy read of QSPI_IFR to synchronize APB and AHB accesses */
> -		(void)qspi_readl(aq, QSPI_IFR);
> +		(void)readl_relaxed(base + QSPI_IFR);
>  
>  		/* Send/Receive data */
>  		if (op->data.dir == SPI_MEM_DATA_IN)
> @@ -321,22 +311,22 @@ static int atmel_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
>  				op->data.buf.out, op->data.nbytes);
>  
>  		/* Release the chip-select */
> -		qspi_writel(aq, QSPI_CR, QSPI_CR_LASTXFER);
> +		writel_relaxed(QSPI_CR_LASTXFER, base + QSPI_CR);
>  	}
>  
>  	/* Poll INSTRuction End status */
> -	sr = qspi_readl(aq, QSPI_SR);
> +	sr = readl_relaxed(base + QSPI_SR);
>  	if ((sr & QSPI_SR_CMD_COMPLETED) == QSPI_SR_CMD_COMPLETED)
>  		return err;
>  
>  	/* Wait for INSTRuction End interrupt */
>  	reinit_completion(&aq->cmd_completion);
>  	aq->pending = sr & QSPI_SR_CMD_COMPLETED;
> -	qspi_writel(aq, QSPI_IER, QSPI_SR_CMD_COMPLETED);
> +	writel_relaxed(QSPI_SR_CMD_COMPLETED, base + QSPI_IER);
>  	if (!wait_for_completion_timeout(&aq->cmd_completion,
>  					 msecs_to_jiffies(1000)))
>  		err = -ETIMEDOUT;
> -	qspi_writel(aq, QSPI_IDR, QSPI_SR_CMD_COMPLETED);
> +	writel_relaxed(QSPI_SR_CMD_COMPLETED, base + QSPI_IDR);
>  
>  	return err;
>  }
> @@ -375,18 +365,20 @@ static int atmel_qspi_setup(struct spi_device *spi)
>  		scbr--;
>  
>  	scr = QSPI_SCR_SCBR(scbr);
> -	qspi_writel(aq, QSPI_SCR, scr);
> +	writel_relaxed(scr, aq->regs + QSPI_SCR);
>  
>  	return 0;
>  }
>  
>  static int atmel_qspi_init(struct atmel_qspi *aq)
>  {
> +	void __iomem *base = aq->regs;
> +
>  	/* Reset the QSPI controller */
> -	qspi_writel(aq, QSPI_CR, QSPI_CR_SWRST);
> +	writel_relaxed(QSPI_CR_SWRST, base + QSPI_CR);
>  
>  	/* Enable the QSPI controller */
> -	qspi_writel(aq, QSPI_CR, QSPI_CR_QSPIEN);
> +	writel_relaxed(QSPI_CR_QSPIEN, base + QSPI_CR);
>  
>  	return 0;
>  }
> @@ -394,10 +386,11 @@ static int atmel_qspi_init(struct atmel_qspi *aq)
>  static irqreturn_t atmel_qspi_interrupt(int irq, void *dev_id)
>  {
>  	struct atmel_qspi *aq = (struct atmel_qspi *)dev_id;
> +	void __iomem *base = aq->regs;
>  	u32 status, mask, pending;
>  
> -	status = qspi_readl(aq, QSPI_SR);
> -	mask = qspi_readl(aq, QSPI_IMR);
> +	status = readl_relaxed(base + QSPI_SR);
> +	mask = readl_relaxed(base + QSPI_IMR);
>  	pending = status & mask;
>  
>  	if (!pending)
> @@ -503,7 +496,7 @@ static int atmel_qspi_remove(struct platform_device *pdev)
>  	struct atmel_qspi *aq = spi_controller_get_devdata(ctrl);
>  
>  	spi_unregister_controller(ctrl);
> -	qspi_writel(aq, QSPI_CR, QSPI_CR_QSPIDIS);
> +	writel_relaxed(QSPI_CR_QSPIDIS, aq->regs + QSPI_CR);
>  	clk_disable_unprepare(aq->clk);
>  	return 0;
>  }
Tudor Ambarus Feb. 2, 2019, 8:44 a.m. UTC | #2 
On 02/02/2019 09:11 AM, Boris Brezillon wrote:
> On Sat, 2 Feb 2019 04:07:19 +0000
> <Tudor.Ambarus@microchip.com> wrote:
> 
>> From: Tudor Ambarus <tudor.ambarus@microchip.com>
>>
>> The wrappers hid that the accesses are relaxed. Drop them.
>>
>> Suggested-by: Boris Brezillon <bbrezillon@kernel.org>
>> Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
>> ---
>> v3: no change
>> v2: new patch
>>
>>  drivers/spi/atmel-quadspi.c | 47 +++++++++++++++++++--------------------------
>>  1 file changed, 20 insertions(+), 27 deletions(-)
>>
>> diff --git a/drivers/spi/atmel-quadspi.c b/drivers/spi/atmel-quadspi.c
>> index feeddcb25e1f..131374db0db4 100644
>> --- a/drivers/spi/atmel-quadspi.c
>> +++ b/drivers/spi/atmel-quadspi.c
>> @@ -175,17 +175,6 @@ static const struct qspi_mode sama5d2_qspi_modes[] = {
>>  	{ 4, 4, 4, QSPI_IFR_WIDTH_QUAD_CMD },
>>  };
>>  
>> -/* Register access functions */
>> -static inline u32 qspi_readl(struct atmel_qspi *aq, u32 reg)
>> -{
>> -	return readl_relaxed(aq->regs + reg);
>> -}
>> -
>> -static inline void qspi_writel(struct atmel_qspi *aq, u32 reg, u32 value)
>> -{
>> -	writel_relaxed(value, aq->regs + reg);
>> -}
>> -
>>  static inline bool is_compatible(const struct spi_mem_op *op,
>>  				 const struct qspi_mode *mode)
>>  {
>> @@ -229,6 +218,7 @@ static bool atmel_qspi_supports_op(struct spi_mem *mem,
>>  static int atmel_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
>>  {
>>  	struct atmel_qspi *aq = spi_controller_get_devdata(mem->spi->master);
>> +	void __iomem *base = aq->regs;
> 
> Can we name this variable regs instead of base or even get rid of it
> and dereference aq->regs in the xxx_relaxed() calls (doesn't look like
> the lines would be over 80 chars even when doing that). With this
> addressed, you can add:
> 
> Reviewed-by: Boris Brezillon <bbrezillon@kernel.org>

I chose to introduce the "base" variable when I have at least 2 dereferences in
a function, as an optimization. In exec_op() for example, there are 6
dereferences of aq->reqs. Why do you prefer keeping aq->regs?
Boris Brezillon Feb. 2, 2019, 1:23 p.m. UTC | #3 
On Sat, 2 Feb 2019 08:44:27 +0000
<Tudor.Ambarus@microchip.com> wrote:

> On 02/02/2019 09:11 AM, Boris Brezillon wrote:
> > On Sat, 2 Feb 2019 04:07:19 +0000
> > <Tudor.Ambarus@microchip.com> wrote:
> >   
> >> From: Tudor Ambarus <tudor.ambarus@microchip.com>
> >>
> >> The wrappers hid that the accesses are relaxed. Drop them.
> >>
> >> Suggested-by: Boris Brezillon <bbrezillon@kernel.org>
> >> Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
> >> ---
> >> v3: no change
> >> v2: new patch
> >>
> >>  drivers/spi/atmel-quadspi.c | 47 +++++++++++++++++++--------------------------
> >>  1 file changed, 20 insertions(+), 27 deletions(-)
> >>
> >> diff --git a/drivers/spi/atmel-quadspi.c b/drivers/spi/atmel-quadspi.c
> >> index feeddcb25e1f..131374db0db4 100644
> >> --- a/drivers/spi/atmel-quadspi.c
> >> +++ b/drivers/spi/atmel-quadspi.c
> >> @@ -175,17 +175,6 @@ static const struct qspi_mode sama5d2_qspi_modes[] = {
> >>  	{ 4, 4, 4, QSPI_IFR_WIDTH_QUAD_CMD },
> >>  };
> >>  
> >> -/* Register access functions */
> >> -static inline u32 qspi_readl(struct atmel_qspi *aq, u32 reg)
> >> -{
> >> -	return readl_relaxed(aq->regs + reg);
> >> -}
> >> -
> >> -static inline void qspi_writel(struct atmel_qspi *aq, u32 reg, u32 value)
> >> -{
> >> -	writel_relaxed(value, aq->regs + reg);
> >> -}
> >> -
> >>  static inline bool is_compatible(const struct spi_mem_op *op,
> >>  				 const struct qspi_mode *mode)
> >>  {
> >> @@ -229,6 +218,7 @@ static bool atmel_qspi_supports_op(struct spi_mem *mem,
> >>  static int atmel_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
> >>  {
> >>  	struct atmel_qspi *aq = spi_controller_get_devdata(mem->spi->master);
> >> +	void __iomem *base = aq->regs;  
> > 
> > Can we name this variable regs instead of base or even get rid of it
> > and dereference aq->regs in the xxx_relaxed() calls (doesn't look like
> > the lines would be over 80 chars even when doing that). With this
> > addressed, you can add:
> > 
> > Reviewed-by: Boris Brezillon <bbrezillon@kernel.org>  
> 
> I chose to introduce the "base" variable when I have at least 2 dereferences in
> a function, as an optimization. In exec_op() for example, there are 6
> dereferences of aq->reqs. Why do you prefer keeping aq->regs?

I tend to not add local variables unless they help improve readability
or optimize things. In this case, I'd expect the compiler to be smart
enough to detect that aq->reqs is used several times and store it in a
register. When it comes to readability, I don't think it improve
things, but that's probably a matter of taste.
diff mbox series

Patch

diff --git a/drivers/spi/atmel-quadspi.c b/drivers/spi/atmel-quadspi.c
index feeddcb25e1f..131374db0db4 100644
--- a/drivers/spi/atmel-quadspi.c
+++ b/drivers/spi/atmel-quadspi.c
@@ -175,17 +175,6 @@  static const struct qspi_mode sama5d2_qspi_modes[] = {
 	{ 4, 4, 4, QSPI_IFR_WIDTH_QUAD_CMD },
 };
 
-/* Register access functions */
-static inline u32 qspi_readl(struct atmel_qspi *aq, u32 reg)
-{
-	return readl_relaxed(aq->regs + reg);
-}
-
-static inline void qspi_writel(struct atmel_qspi *aq, u32 reg, u32 value)
-{
-	writel_relaxed(value, aq->regs + reg);
-}
-
 static inline bool is_compatible(const struct spi_mem_op *op,
 				 const struct qspi_mode *mode)
 {
@@ -229,6 +218,7 @@  static bool atmel_qspi_supports_op(struct spi_mem *mem,
 static int atmel_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
 {
 	struct atmel_qspi *aq = spi_controller_get_devdata(mem->spi->master);
+	void __iomem *base = aq->regs;
 	int mode;
 	u32 dummy_cycles = 0;
 	u32 iar, icr, ifr, sr;
@@ -240,7 +230,7 @@  static int atmel_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
 
 	/* Set the QSPI controller in Serial Memory Mode */
 	if (aq->smm != QSPI_MR_SMM) {
-		qspi_writel(aq, QSPI_MR, QSPI_MR_SMM);
+		writel_relaxed(QSPI_MR_SMM, base + QSPI_MR);
 		aq->smm = QSPI_MR_SMM;
 	}
 
@@ -300,17 +290,17 @@  static int atmel_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
 		ifr |= QSPI_IFR_TFRTYP_TRSFR_WRITE;
 
 	/* Clear pending interrupts */
-	(void)qspi_readl(aq, QSPI_SR);
+	(void)readl_relaxed(base + QSPI_SR);
 
 	/* Set QSPI Instruction Frame registers */
-	qspi_writel(aq, QSPI_IAR, iar);
-	qspi_writel(aq, QSPI_ICR, icr);
-	qspi_writel(aq, QSPI_IFR, ifr);
+	writel_relaxed(iar, base + QSPI_IAR);
+	writel_relaxed(icr, base + QSPI_ICR);
+	writel_relaxed(ifr, base + QSPI_IFR);
 
 	/* Skip to the final steps if there is no data */
 	if (op->data.nbytes) {
 		/* Dummy read of QSPI_IFR to synchronize APB and AHB accesses */
-		(void)qspi_readl(aq, QSPI_IFR);
+		(void)readl_relaxed(base + QSPI_IFR);
 
 		/* Send/Receive data */
 		if (op->data.dir == SPI_MEM_DATA_IN)
@@ -321,22 +311,22 @@  static int atmel_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
 				op->data.buf.out, op->data.nbytes);
 
 		/* Release the chip-select */
-		qspi_writel(aq, QSPI_CR, QSPI_CR_LASTXFER);
+		writel_relaxed(QSPI_CR_LASTXFER, base + QSPI_CR);
 	}
 
 	/* Poll INSTRuction End status */
-	sr = qspi_readl(aq, QSPI_SR);
+	sr = readl_relaxed(base + QSPI_SR);
 	if ((sr & QSPI_SR_CMD_COMPLETED) == QSPI_SR_CMD_COMPLETED)
 		return err;
 
 	/* Wait for INSTRuction End interrupt */
 	reinit_completion(&aq->cmd_completion);
 	aq->pending = sr & QSPI_SR_CMD_COMPLETED;
-	qspi_writel(aq, QSPI_IER, QSPI_SR_CMD_COMPLETED);
+	writel_relaxed(QSPI_SR_CMD_COMPLETED, base + QSPI_IER);
 	if (!wait_for_completion_timeout(&aq->cmd_completion,
 					 msecs_to_jiffies(1000)))
 		err = -ETIMEDOUT;
-	qspi_writel(aq, QSPI_IDR, QSPI_SR_CMD_COMPLETED);
+	writel_relaxed(QSPI_SR_CMD_COMPLETED, base + QSPI_IDR);
 
 	return err;
 }
@@ -375,18 +365,20 @@  static int atmel_qspi_setup(struct spi_device *spi)
 		scbr--;
 
 	scr = QSPI_SCR_SCBR(scbr);
-	qspi_writel(aq, QSPI_SCR, scr);
+	writel_relaxed(scr, aq->regs + QSPI_SCR);
 
 	return 0;
 }
 
 static int atmel_qspi_init(struct atmel_qspi *aq)
 {
+	void __iomem *base = aq->regs;
+
 	/* Reset the QSPI controller */
-	qspi_writel(aq, QSPI_CR, QSPI_CR_SWRST);
+	writel_relaxed(QSPI_CR_SWRST, base + QSPI_CR);
 
 	/* Enable the QSPI controller */
-	qspi_writel(aq, QSPI_CR, QSPI_CR_QSPIEN);
+	writel_relaxed(QSPI_CR_QSPIEN, base + QSPI_CR);
 
 	return 0;
 }
@@ -394,10 +386,11 @@  static int atmel_qspi_init(struct atmel_qspi *aq)
 static irqreturn_t atmel_qspi_interrupt(int irq, void *dev_id)
 {
 	struct atmel_qspi *aq = (struct atmel_qspi *)dev_id;
+	void __iomem *base = aq->regs;
 	u32 status, mask, pending;
 
-	status = qspi_readl(aq, QSPI_SR);
-	mask = qspi_readl(aq, QSPI_IMR);
+	status = readl_relaxed(base + QSPI_SR);
+	mask = readl_relaxed(base + QSPI_IMR);
 	pending = status & mask;
 
 	if (!pending)
@@ -503,7 +496,7 @@  static int atmel_qspi_remove(struct platform_device *pdev)
 	struct atmel_qspi *aq = spi_controller_get_devdata(ctrl);
 
 	spi_unregister_controller(ctrl);
-	qspi_writel(aq, QSPI_CR, QSPI_CR_QSPIDIS);
+	writel_relaxed(QSPI_CR_QSPIDIS, aq->regs + QSPI_CR);
 	clk_disable_unprepare(aq->clk);
 	return 0;
 }