Re: [PATCH v3 20/25] clk: bcm: rpi: Add an enum for the firmware clocks

From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
To: Maxime Ripard <maxime@cerno.tech>
Cc: linux-rpi-kernel@lists.infradead.org,
	bcm-kernel-feedback-list@broadcom.com,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	Dave Stevenson <dave.stevenson@raspberrypi.com>,
	Tim Gover <tim.gover@raspberrypi.com>,
	Phil Elwell <phil@raspberrypi.com>
Subject: Re: [PATCH v3 20/25] clk: bcm: rpi: Add an enum for the firmware clocks
Date: Fri, 05 Jun 2020 15:09:15 +0200	[thread overview]
Message-ID: <ef54a57d7a7475a3e052805d1d1d3cd81e36569d.camel@suse.de> (raw)
In-Reply-To: <d8be3a45491224e0c91355131a9bcf605f38fb76.camel@suse.de>

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Hi Maxime,

On Fri, 2020-06-05 at 14:04 +0200, Nicolas Saenz Julienne wrote:
> On Wed, 2020-05-27 at 17:45 +0200, Maxime Ripard wrote:
> > While the firmware allows us to discover the available clocks, we need to
> > discriminate those clocks to only register the ones meaningful to Linux.
> > The firmware also doesn't provide a clock name, so having a list of the ID
> > will help us to give clocks a proper name later on.
> > 
> > Signed-off-by: Maxime Ripard <maxime@cerno.tech>
> > ---
> >  drivers/clk/bcm/clk-raspberrypi.c | 23 +++++++++++++++++++----
> >  1 file changed, 19 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/clk/bcm/clk-raspberrypi.c b/drivers/clk/bcm/clk-
> > raspberrypi.c
> > index 5f4e2d49432f..eebd16040f8a 100644
> > --- a/drivers/clk/bcm/clk-raspberrypi.c
> > +++ b/drivers/clk/bcm/clk-raspberrypi.c
> > @@ -18,7 +18,23 @@
> >  
> >  #include <soc/bcm2835/raspberrypi-firmware.h>
> >  
> > -#define RPI_FIRMWARE_ARM_CLK_ID		0x00000003
> > +enum rpi_firmware_clk_id {
> > +	RPI_FIRMWARE_EMMC_CLK_ID = 1,
> > +	RPI_FIRMWARE_UART_CLK_ID,
> > +	RPI_FIRMWARE_ARM_CLK_ID,
> > +	RPI_FIRMWARE_CORE_CLK_ID,
> > +	RPI_FIRMWARE_V3D_CLK_ID,
> > +	RPI_FIRMWARE_H264_CLK_ID,
> > +	RPI_FIRMWARE_ISP_CLK_ID,
> > +	RPI_FIRMWARE_SDRAM_CLK_ID,
> > +	RPI_FIRMWARE_PIXEL_CLK_ID,
> > +	RPI_FIRMWARE_PWM_CLK_ID,
> > +	RPI_FIRMWARE_HEVC_CLK_ID,
> > +	RPI_FIRMWARE_EMMC2_CLK_ID,
> > +	RPI_FIRMWARE_M2MC_CLK_ID,
> > +	RPI_FIRMWARE_PIXEL_BVB_CLK_ID,
> > +	RPI_FIRMWARE_NUM_CLK_ID,
> > +};
> >  
> >  #define RPI_FIRMWARE_STATE_ENABLE_BIT	BIT(0)
> >  #define RPI_FIRMWARE_STATE_WAIT_BIT	BIT(1)
> > @@ -31,8 +47,6 @@
> >  
> >  #define A2W_PLL_FRAC_BITS		20
> >  
> > -#define NUM_FW_CLKS			16
> > -
> >  struct raspberrypi_clk {
> >  	struct device *dev;
> >  	struct rpi_firmware *firmware;
> > @@ -320,7 +334,8 @@ static int raspberrypi_clk_probe(struct platform_device
> > *pdev)
> >  	rpi->firmware = firmware;
> >  	platform_set_drvdata(pdev, rpi);
> >  
> > -	clk_data = devm_kzalloc(dev, struct_size(clk_data, hws, NUM_FW_CLKS),
> > +	clk_data = devm_kzalloc(dev, struct_size(clk_data, hws,
> > +						 RPI_FIRMWARE_NUM_CLK_ID),
> 
> nit: you're allocating one structure too many right?

Nevermind this comment, as pointed out privately by Phil Elwell, I forgot the
firmware clk description structure starts at 0. So we need to make space for
that.

It would maybe make sense to add RPI_FIRMWARE_RESERVED_CLK_ID above the EMMC
clk entry. Although it's just a suggestion.

> Acked-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> 
> Regards,
> Nicolas
> 

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