Re: [PATCH v6 03/13] media: hantro: Use syscon instead of 'ctrl' register

[Philipp Zabel <pza@pengutronix.de>]

On Thu, Mar 18, 2021 at 09:20:36AM +0100, Benjamin Gaignard wrote:
> In order to be able to share the control hardware block between
> VPUs use a syscon instead a ioremap it in the driver.
> To keep the compatibility with older DT if 'nxp,imx8mq-vpu-ctrl'
> phandle is not found look at 'ctrl' reg-name.
> With the method it becomes useless to provide a list of register
> names so remove it.
> 
> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
> ---
> version 5:
>  - use syscon instead of VPU reset driver.
>  - if DT doesn't provide syscon keep backward compatibilty by using
>    'ctrl' reg-name.
> 
>  drivers/staging/media/hantro/hantro.h       |  5 +-
>  drivers/staging/media/hantro/imx8m_vpu_hw.c | 52 ++++++++++++---------
>  2 files changed, 34 insertions(+), 23 deletions(-)
> 
> diff --git a/drivers/staging/media/hantro/hantro.h b/drivers/staging/media/hantro/hantro.h
> index 65f9f7ea7dcf..a99a96b84b5e 100644
> --- a/drivers/staging/media/hantro/hantro.h
> +++ b/drivers/staging/media/hantro/hantro.h
> @@ -13,6 +13,7 @@
>  #define HANTRO_H_
>  
>  #include <linux/platform_device.h>
> +#include <linux/regmap.h>
>  #include <linux/videodev2.h>
>  #include <linux/wait.h>
>  #include <linux/clk.h>
> @@ -167,7 +168,7 @@ hantro_vdev_to_func(struct video_device *vdev)
>   * @reg_bases:		Mapped addresses of VPU registers.
>   * @enc_base:		Mapped address of VPU encoder register for convenience.
>   * @dec_base:		Mapped address of VPU decoder register for convenience.
> - * @ctrl_base:		Mapped address of VPU control block.
> + * @ctrl_base:		Regmap of VPU control block.
>   * @vpu_mutex:		Mutex to synchronize V4L2 calls.
>   * @irqlock:		Spinlock to synchronize access to data structures
>   *			shared with interrupt handlers.
> @@ -186,7 +187,7 @@ struct hantro_dev {
>  	void __iomem **reg_bases;
>  	void __iomem *enc_base;
>  	void __iomem *dec_base;
> -	void __iomem *ctrl_base;
> +	struct regmap *ctrl_base;
>  
>  	struct mutex vpu_mutex;	/* video_device lock */
>  	spinlock_t irqlock;
> diff --git a/drivers/staging/media/hantro/imx8m_vpu_hw.c b/drivers/staging/media/hantro/imx8m_vpu_hw.c
> index c222de075ef4..bd9d135dd440 100644
> --- a/drivers/staging/media/hantro/imx8m_vpu_hw.c
> +++ b/drivers/staging/media/hantro/imx8m_vpu_hw.c
> @@ -7,6 +7,7 @@
>  
>  #include <linux/clk.h>
>  #include <linux/delay.h>
> +#include <linux/mfd/syscon.h>
>  
>  #include "hantro.h"
>  #include "hantro_jpeg.h"
> @@ -24,30 +25,28 @@
>  #define CTRL_G1_PP_FUSE		0x0c
>  #define CTRL_G2_DEC_FUSE	0x10
>  
> +static const struct regmap_config ctrl_regmap_ctrl = {
> +	.reg_bits = 32,
> +	.val_bits = 32,
> +	.reg_stride = 0x14,
> +};
> +
>  static void imx8m_soft_reset(struct hantro_dev *vpu, u32 reset_bits)
>  {
> -	u32 val;
> -
>  	/* Assert */
> -	val = readl(vpu->ctrl_base + CTRL_SOFT_RESET);
> -	val &= ~reset_bits;
> -	writel(val, vpu->ctrl_base + CTRL_SOFT_RESET);
> +	regmap_update_bits(vpu->ctrl_base, CTRL_SOFT_RESET, reset_bits, 0);
>  
>  	udelay(2);
>  
>  	/* Release */
> -	val = readl(vpu->ctrl_base + CTRL_SOFT_RESET);
> -	val |= reset_bits;
> -	writel(val, vpu->ctrl_base + CTRL_SOFT_RESET);
> +	regmap_update_bits(vpu->ctrl_base, CTRL_SOFT_RESET,
> +			   reset_bits, reset_bits);
>  }
>  
>  static void imx8m_clk_enable(struct hantro_dev *vpu, u32 clock_bits)
>  {
> -	u32 val;
> -
> -	val = readl(vpu->ctrl_base + CTRL_CLOCK_ENABLE);
> -	val |= clock_bits;
> -	writel(val, vpu->ctrl_base + CTRL_CLOCK_ENABLE);
> +	regmap_update_bits(vpu->ctrl_base, CTRL_CLOCK_ENABLE,
> +			   clock_bits, clock_bits);
>  }
>  
>  static int imx8mq_runtime_resume(struct hantro_dev *vpu)
> @@ -64,9 +63,9 @@ static int imx8mq_runtime_resume(struct hantro_dev *vpu)
>  	imx8m_clk_enable(vpu, CLOCK_G1 | CLOCK_G2);
>  
>  	/* Set values of the fuse registers */
> -	writel(0xffffffff, vpu->ctrl_base + CTRL_G1_DEC_FUSE);
> -	writel(0xffffffff, vpu->ctrl_base + CTRL_G1_PP_FUSE);
> -	writel(0xffffffff, vpu->ctrl_base + CTRL_G2_DEC_FUSE);
> +	regmap_write(vpu->ctrl_base, CTRL_G1_DEC_FUSE, 0xffffffff);
> +	regmap_write(vpu->ctrl_base, CTRL_G1_PP_FUSE, 0xffffffff);
> +	regmap_write(vpu->ctrl_base, CTRL_G2_DEC_FUSE, 0xffffffff);
>  
>  	clk_bulk_disable_unprepare(vpu->variant->num_clocks, vpu->clocks);
>  
> @@ -150,8 +149,22 @@ static irqreturn_t imx8m_vpu_g1_irq(int irq, void *dev_id)
>  
>  static int imx8mq_vpu_hw_init(struct hantro_dev *vpu)
>  {
> -	vpu->dec_base = vpu->reg_bases[0];
> -	vpu->ctrl_base = vpu->reg_bases[vpu->variant->num_regs - 1];
> +	struct device_node *np = vpu->dev->of_node;
> +
> +	vpu->ctrl_base = syscon_regmap_lookup_by_phandle(np, "nxp,imx8mq-vpu-ctrl");

I think calling this nxp,imx8m-vpu-ctrl would allow to share this with
i.MX8MM later. Otherwise,

Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>

thanks
Philipp