2021-05-26 20:39:14

by Andy Shevchenko

[permalink] [raw]
Subject: [PATCH v2 1/2] can: mcp251xfd: Try to get crystal clock rate from property

In some configurations, mainly ACPI-based, the clock frequency of the device
is supplied by very well established 'clock-frequency' property. Hence, try
to get it from the property at last if no other providers are available.

Signed-off-by: Andy Shevchenko <[email protected]>
---
v2: new patch
drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
index e0ae00e34c7b..e42f87c3f2ec 100644
--- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
+++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
@@ -2856,7 +2856,7 @@ static int mcp251xfd_probe(struct spi_device *spi)
struct gpio_desc *rx_int;
struct regulator *reg_vdd, *reg_xceiver;
struct clk *clk;
- u32 freq;
+ u32 freq, rate;
int err;

if (!spi->irq)
@@ -2883,11 +2883,16 @@ static int mcp251xfd_probe(struct spi_device *spi)
return dev_err_probe(&spi->dev, PTR_ERR(reg_xceiver),
"Failed to get Transceiver regulator!\n");

- clk = devm_clk_get(&spi->dev, NULL);
+ /* Always ask for fixed clock rate from a property. */
+ device_property_read_u32(&spi->dev, "clock-frequency", &rate);
+
+ clk = devm_clk_get_optional(&spi->dev, NULL);
if (IS_ERR(clk))
return dev_err_probe(&spi->dev, PTR_ERR(clk),
"Failed to get Oscillator (clock)!\n");
freq = clk_get_rate(clk);
+ if (freq == 0)
+ freq = rate;

/* Sanity check */
if (freq < MCP251XFD_SYSCLOCK_HZ_MIN ||
--
2.30.2


2021-05-26 20:39:27

by Andy Shevchenko

[permalink] [raw]
Subject: [PATCH v2 2/2] can: mcp251xfd: Fix header block to clarify independence from OF

The driver is neither dependent on OF, nor it requires any OF headers.
Fix header block to clarify independence from OF.

Signed-off-by: Andy Shevchenko <[email protected]>
---
v2: included property.h
drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
index e42f87c3f2ec..e919f7e4d566 100644
--- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
+++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
@@ -15,10 +15,10 @@
#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/device.h>
+#include <linux/mod_devicetable.h>
#include <linux/module.h>
-#include <linux/of.h>
-#include <linux/of_device.h>
#include <linux/pm_runtime.h>
+#include <linux/property.h>

#include <asm/unaligned.h>

--
2.30.2

2021-05-31 08:49:21

by Marc Kleine-Budde

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] can: mcp251xfd: Try to get crystal clock rate from property

On 26.05.2021 22:33:26, Andy Shevchenko wrote:
> In some configurations, mainly ACPI-based, the clock frequency of the device
> is supplied by very well established 'clock-frequency' property. Hence, try
> to get it from the property at last if no other providers are available.
>
> Signed-off-by: Andy Shevchenko <[email protected]>
> ---
> v2: new patch
> drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
> index e0ae00e34c7b..e42f87c3f2ec 100644
> --- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
> +++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
> @@ -2856,7 +2856,7 @@ static int mcp251xfd_probe(struct spi_device *spi)
> struct gpio_desc *rx_int;
> struct regulator *reg_vdd, *reg_xceiver;
> struct clk *clk;
> - u32 freq;
> + u32 freq, rate;
> int err;
>
> if (!spi->irq)
> @@ -2883,11 +2883,16 @@ static int mcp251xfd_probe(struct spi_device *spi)
> return dev_err_probe(&spi->dev, PTR_ERR(reg_xceiver),
> "Failed to get Transceiver regulator!\n");
>
> - clk = devm_clk_get(&spi->dev, NULL);
> + /* Always ask for fixed clock rate from a property. */
> + device_property_read_u32(&spi->dev, "clock-frequency", &rate);

what about error handling....?

> +
> + clk = devm_clk_get_optional(&spi->dev, NULL);
> if (IS_ERR(clk))
> return dev_err_probe(&spi->dev, PTR_ERR(clk),
> "Failed to get Oscillator (clock)!\n");
> freq = clk_get_rate(clk);
> + if (freq == 0)
> + freq = rate;

... this means we don't fail if there is neither a clk nor a
clock-frequency property. I've send a v3 to fix this.

>
> /* Sanity check */
> if (freq < MCP251XFD_SYSCLOCK_HZ_MIN ||
> --
> 2.30.2
>
>

Marc

--
Pengutronix e.K. | Marc Kleine-Budde |
Embedded Linux | https://www.pengutronix.de |
Vertretung West/Dortmund | Phone: +49-231-2826-924 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |


Attachments:
(No filename) (2.12 kB)
signature.asc (499.00 B)
Download all attachments

2021-05-31 10:01:53

by Andy Shevchenko

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] can: mcp251xfd: Try to get crystal clock rate from property

On Mon, May 31, 2021 at 10:47:20AM +0200, Marc Kleine-Budde wrote:
> On 26.05.2021 22:33:26, Andy Shevchenko wrote:
> > In some configurations, mainly ACPI-based, the clock frequency of the device
> > is supplied by very well established 'clock-frequency' property. Hence, try
> > to get it from the property at last if no other providers are available.

> > return dev_err_probe(&spi->dev, PTR_ERR(reg_xceiver),
> > "Failed to get Transceiver regulator!\n");
> >
> > - clk = devm_clk_get(&spi->dev, NULL);
> > + /* Always ask for fixed clock rate from a property. */
> > + device_property_read_u32(&spi->dev, "clock-frequency", &rate);
>
> what about error handling....?

Not needed, but rate should be assigned to 0, which is missed.

> > + clk = devm_clk_get_optional(&spi->dev, NULL);
> > if (IS_ERR(clk))
> > return dev_err_probe(&spi->dev, PTR_ERR(clk),
> > "Failed to get Oscillator (clock)!\n");
> > freq = clk_get_rate(clk);
> > + if (freq == 0)
> > + freq = rate;
>
> ... this means we don't fail if there is neither a clk nor a
> clock-frequency property.

The following will check for it (which is already in the code)

if (freq <= MCP251XFD_SYSCLOCK_HZ_MAX / MCP251XFD_OSC_PLL_MULTIPLIER) {

> I've send a v3 to fix this.

You mean I have to send v3?
Sure!


--
With Best Regards,
Andy Shevchenko


2021-05-31 10:04:19

by Andy Shevchenko

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] can: mcp251xfd: Try to get crystal clock rate from property

On Mon, May 31, 2021 at 12:58:29PM +0300, Andy Shevchenko wrote:
> On Mon, May 31, 2021 at 10:47:20AM +0200, Marc Kleine-Budde wrote:
> > On 26.05.2021 22:33:26, Andy Shevchenko wrote:
> > > In some configurations, mainly ACPI-based, the clock frequency of the device
> > > is supplied by very well established 'clock-frequency' property. Hence, try
> > > to get it from the property at last if no other providers are available.
>
> > > return dev_err_probe(&spi->dev, PTR_ERR(reg_xceiver),
> > > "Failed to get Transceiver regulator!\n");
> > >
> > > - clk = devm_clk_get(&spi->dev, NULL);
> > > + /* Always ask for fixed clock rate from a property. */
> > > + device_property_read_u32(&spi->dev, "clock-frequency", &rate);
> >
> > what about error handling....?
>
> Not needed, but rate should be assigned to 0, which is missed.
>
> > > + clk = devm_clk_get_optional(&spi->dev, NULL);
> > > if (IS_ERR(clk))
> > > return dev_err_probe(&spi->dev, PTR_ERR(clk),
> > > "Failed to get Oscillator (clock)!\n");
> > > freq = clk_get_rate(clk);
> > > + if (freq == 0)
> > > + freq = rate;
> >
> > ... this means we don't fail if there is neither a clk nor a
> > clock-frequency property.
>
> The following will check for it (which is already in the code)
>
> if (freq <= MCP251XFD_SYSCLOCK_HZ_MAX / MCP251XFD_OSC_PLL_MULTIPLIER) {

Even before, actually,

/* Sanity check */
if (freq < MCP251XFD_SYSCLOCK_HZ_MIN ||
freq > MCP251XFD_SYSCLOCK_HZ_MAX) {


> > I've send a v3 to fix this.
>
> You mean I have to send v3?
> Sure!

So, I am going to send a v3 with amended commit message and assigning rate
to 0.

--
With Best Regards,
Andy Shevchenko


2021-05-31 10:04:31

by Marc Kleine-Budde

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] can: mcp251xfd: Try to get crystal clock rate from property

On 31.05.2021 12:58:29, Andy Shevchenko wrote:
> On Mon, May 31, 2021 at 10:47:20AM +0200, Marc Kleine-Budde wrote:
> > On 26.05.2021 22:33:26, Andy Shevchenko wrote:
> > > In some configurations, mainly ACPI-based, the clock frequency of the device
> > > is supplied by very well established 'clock-frequency' property. Hence, try
> > > to get it from the property at last if no other providers are available.
>
> > > return dev_err_probe(&spi->dev, PTR_ERR(reg_xceiver),
> > > "Failed to get Transceiver regulator!\n");
> > >
> > > - clk = devm_clk_get(&spi->dev, NULL);
> > > + /* Always ask for fixed clock rate from a property. */
> > > + device_property_read_u32(&spi->dev, "clock-frequency", &rate);
> >
> > what about error handling....?
>
> Not needed, but rate should be assigned to 0, which is missed.
>
> > > + clk = devm_clk_get_optional(&spi->dev, NULL);
> > > if (IS_ERR(clk))
> > > return dev_err_probe(&spi->dev, PTR_ERR(clk),
> > > "Failed to get Oscillator (clock)!\n");
> > > freq = clk_get_rate(clk);
> > > + if (freq == 0)
> > > + freq = rate;
> >
> > ... this means we don't fail if there is neither a clk nor a
> > clock-frequency property.
>
> The following will check for it (which is already in the code)
>
> if (freq <= MCP251XFD_SYSCLOCK_HZ_MAX / MCP251XFD_OSC_PLL_MULTIPLIER) {

Good point.

> > I've send a v3 to fix this.
>
> You mean I have to send v3?
> Sure!

I have send a v3, see:

https://lore.kernel.org/r/[email protected]

Marc

--
Pengutronix e.K. | Marc Kleine-Budde |
Embedded Linux | https://www.pengutronix.de |
Vertretung West/Dortmund | Phone: +49-231-2826-924 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |


Attachments:
(No filename) (1.81 kB)
signature.asc (499.00 B)
Download all attachments