Date: Wed, 20 Mar 2024 15:57:39 +0000
From: Bryan O'Donoghue <bryan.odonoghue@...aro.org>
To: Depeng Shao <quic_depengs@...cinc.com>, rfoss@...nel.org,
 todor.too@...il.com, andersson@...nel.org, konrad.dybcio@...aro.org,
 mchehab@...nel.org, quic_yon@...cinc.com
Cc: linux-kernel@...r.kernel.org, linux-media@...r.kernel.org,
 linux-arm-msm@...r.kernel.org
Subject: Re: [PATCH v2 6/8] media: qcom: camss: Add new VFE driver for SM8550

On 20/03/2024 14:11, Depeng Shao wrote:
> From: Yongsheng Li <quic_yon@...cinc.com>
> 
> Add IFE driver for SM8550, the main difference with
> old HW is register offset is different, register
> update, reset and buf done is moved to CSID. And
> the image address support 36 bits, so need to right
> shift the image address when configuring the write
> master.
> 
> Signed-off-by: Yongsheng Li <quic_yon@...cinc.com>
> Co-developed-by: Depeng Shao <quic_depengs@...cinc.com>
> Signed-off-by: Depeng Shao <quic_depengs@...cinc.com>

Same comment with your co-developed and SOB

> ---
>   drivers/media/platform/qcom/camss/Makefile    |   1 +
>   .../media/platform/qcom/camss/camss-vfe-780.c | 455 ++++++++++++++++++
>   drivers/media/platform/qcom/camss/camss-vfe.h |   1 +
>   3 files changed, 457 insertions(+)
>   create mode 100644 drivers/media/platform/qcom/camss/camss-vfe-780.c
> 
> diff --git a/drivers/media/platform/qcom/camss/Makefile b/drivers/media/platform/qcom/camss/Makefile
> index c5fcd6eec0f2..ac40bbab18a3 100644
> --- a/drivers/media/platform/qcom/camss/Makefile
> +++ b/drivers/media/platform/qcom/camss/Makefile
> @@ -18,6 +18,7 @@ qcom-camss-objs += \
>   		camss-vfe-4-8.o \
>   		camss-vfe-17x.o \
>   		camss-vfe-480.o \
> +		camss-vfe-780.o \
>   		camss-vfe-gen1.o \
>   		camss-vfe.o \
>   		camss-video.o \
> diff --git a/drivers/media/platform/qcom/camss/camss-vfe-780.c b/drivers/media/platform/qcom/camss/camss-vfe-780.c
> new file mode 100644
> index 000000000000..a78647f23c8c
> --- /dev/null
> +++ b/drivers/media/platform/qcom/camss/camss-vfe-780.c
> @@ -0,0 +1,455 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * camss-vfe-780.c
> + *
> + * Qualcomm MSM Camera Subsystem - VFE (Video Front End) Module v780 (SM8550)
> + *
> + * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/iopoll.h>
> +
> +#include "camss.h"
> +#include "camss-vfe.h"
> +
> +#define VFE_HW_VERSION			(vfe_is_lite(vfe) ? 0x1000 : 0x0)
> +
> +#define VFE_IRQ_CMD			(vfe_is_lite(vfe) ? 0x1038 : 0x30)
> +#define     IRQ_CMD_GLOBAL_CLEAR	BIT(0)
> +
> +#define VFE_IRQ_MASK(n)			((vfe_is_lite(vfe) ? 0x1024 : 0x34) + (n) * 4)
> +#define	    IRQ_MASK_0_BUS_TOP_IRQ	(vfe_is_lite(vfe) ? BIT(0) | BIT(1) | BIT(2) : \
> +						BIT(0) | BIT(4) | BIT(18))
> +#define	    IRQ_MASK_1_BUS_TOP_IRQ(n)	(vfe_is_lite(vfe) ? BIT(2 * n + 2) | BIT(2 * n + 3) : \
> +						BIT(2 * n + 8) | BIT(2 * n + 9))
> +#define VFE_IRQ_CLEAR(n)		((vfe_is_lite(vfe) ? 0x102C : 0x3C) + (n) * 4)
> +#define VFE_IRQ_STATUS(n)		((vfe_is_lite(vfe) ? 0x101C : 0x44) + (n) * 4)
> +
> +#define BUS_REG_BASE			(vfe_is_lite(vfe) ? 0x1200 : 0xC00)
> +
> +#define VFE_BUS_WM_CGC_OVERRIDE		(BUS_REG_BASE + 0x08)
> +#define		WM_CGC_OVERRIDE_ALL	(0x7FFFFFF)
> +
> +#define VFE_BUS_WM_TEST_BUS_CTRL	(BUS_REG_BASE + 0xdc)
> +
> +#define VFE_BUS_WM_CFG(n)		(BUS_REG_BASE + 0x200 + (n) * 0x100)
> +#define		WM_CFG_EN			(0)
> +#define		WM_VIR_FRM_EN		(1)
> +#define		WM_CFG_MODE			(16)
> +#define			MODE_QCOM_PLAIN	(0)
> +#define			MODE_MIPI_RAW	(1)
> +#define VFE_BUS_WM_IMAGE_ADDR(n)	(BUS_REG_BASE + 0x204 + (n) * 0x100)
> +#define VFE_BUS_WM_FRAME_INCR(n)	(BUS_REG_BASE + 0x208 + (n) * 0x100)
> +#define VFE_BUS_WM_IMAGE_CFG_0(n)	(BUS_REG_BASE + 0x20c + (n) * 0x100)
> +#define                WM_IMAGE_CFG_0_DEFAULT_WIDTH    (0xFFFF)
> +#define VFE_BUS_WM_IMAGE_CFG_1(n)	(BUS_REG_BASE + 0x210 + (n) * 0x100)
> +#define VFE_BUS_WM_IMAGE_CFG_2(n)	(BUS_REG_BASE + 0x214 + (n) * 0x100)
> +#define                WM_IMAGE_CFG_2_DEFAULT_STRIDE    (0xFFFF)
> +#define VFE_BUS_WM_PACKER_CFG(n)	(BUS_REG_BASE + 0x218 + (n) * 0x100)
> +#define VFE_BUS_WM_HEADER_ADDR(n)	(BUS_REG_BASE + 0x220 + (n) * 0x100)
> +#define VFE_BUS_WM_HEADER_INCR(n)	(BUS_REG_BASE + 0x224 + (n) * 0x100)
> +#define VFE_BUS_WM_HEADER_CFG(n)	(BUS_REG_BASE + 0x228 + (n) * 0x100)
> +
> +#define VFE_BUS_WM_IRQ_SUBSAMPLE_PERIOD(n)	(BUS_REG_BASE + 0x230 + (n) * 0x100)
> +#define VFE_BUS_WM_IRQ_SUBSAMPLE_PATTERN(n)	(BUS_REG_BASE + 0x234 + (n) * 0x100)
> +#define VFE_BUS_WM_FRAMEDROP_PERIOD(n)		(BUS_REG_BASE + 0x238 + (n) * 0x100)
> +#define VFE_BUS_WM_FRAMEDROP_PATTERN(n)		(BUS_REG_BASE + 0x23c + (n) * 0x100)
> +
> +#define VFE_BUS_WM_MMU_PREFETCH_CFG(n)	(BUS_REG_BASE + 0x260 + (n) * 0x100)
> +#define VFE_BUS_WM_MMU_PREFETCH_MAX_OFFSET(n)	(BUS_REG_BASE + 0x264 + (n) * 0x100)
> +#define VFE_BUS_WM_SYSTEM_CACHE_CFG(n)	(BUS_REG_BASE + 0x268 + (n) * 0x100)
> +
> +
> +/* for titan 780, each bus client is hardcoded to a specific path */
> +#define RDI_WM(n)			((vfe_is_lite(vfe) ? 0 : 23) + (n))

No admixture of hex and decimal please.

> +
> +#define MAX_VFE_OUTPUT_LINES	4
> +#define MAX_VFE_ACT_BUF	1
> +
> +static u32 vfe_hw_version(struct vfe_device *vfe)
> +{
> +	u32 hw_version = readl_relaxed(vfe->base + VFE_HW_VERSION);
> +
> +	u32 gen = (hw_version >> 28) & 0xF;
> +	u32 rev = (hw_version >> 16) & 0xFFF;
> +	u32 step = hw_version & 0xFFFF;
> +
> +	dev_info(vfe->camss->dev, "VFE HW Version = %u.%u.%u\n", gen, rev, step);
> +
> +	return hw_version;
> +}

Same comment as with CSID, its time to rationalise all of this 
replicated code down to one place, instead of proliferating it further.

> +static void vfe_global_reset(struct vfe_device *vfe)
> +{
> +}
> +
> +static void vfe_wm_start(struct vfe_device *vfe, u8 wm, struct vfe_line *line)
> +{
> +	struct v4l2_pix_format_mplane *pix =
> +		&line->video_out.active_fmt.fmt.pix_mp;
> +
> +	wm = RDI_WM(wm); /* map to actual WM used (from wm=RDI index) */
> +
> +	/* no clock gating at bus input */
> +	writel_relaxed(0, vfe->base + VFE_BUS_WM_CGC_OVERRIDE);
> +
> +	writel_relaxed(0x0, vfe->base + VFE_BUS_WM_TEST_BUS_CTRL);
> +
> +	writel_relaxed(ALIGN(pix->plane_fmt[0].bytesperline, 16) * pix->height >> 8,
> +		       vfe->base + VFE_BUS_WM_FRAME_INCR(wm));
> +	writel_relaxed((WM_IMAGE_CFG_0_DEFAULT_WIDTH & 0xFFFF),
> +		       vfe->base + VFE_BUS_WM_IMAGE_CFG_0(wm));
> +	writel_relaxed(WM_IMAGE_CFG_2_DEFAULT_STRIDE,
> +		       vfe->base + VFE_BUS_WM_IMAGE_CFG_2(wm));
> +	writel_relaxed(0, vfe->base + VFE_BUS_WM_PACKER_CFG(wm));
> +
> +	/* no dropped frames, one irq per frame */
> +	writel_relaxed(0, vfe->base + VFE_BUS_WM_FRAMEDROP_PERIOD(wm));
> +	writel_relaxed(1, vfe->base + VFE_BUS_WM_FRAMEDROP_PATTERN(wm));
> +	writel_relaxed(0, vfe->base + VFE_BUS_WM_IRQ_SUBSAMPLE_PERIOD(wm));
> +	writel_relaxed(1, vfe->base + VFE_BUS_WM_IRQ_SUBSAMPLE_PATTERN(wm));
> +
> +	writel_relaxed(1, vfe->base + VFE_BUS_WM_MMU_PREFETCH_CFG(wm));
> +	writel_relaxed(0xFFFFFFFF, vfe->base + VFE_BUS_WM_MMU_PREFETCH_MAX_OFFSET(wm));
> +
> +	writel_relaxed(1 << WM_CFG_EN | MODE_MIPI_RAW << WM_CFG_MODE,
> +		       vfe->base + VFE_BUS_WM_CFG(wm));
> +}
> +
> +static void vfe_wm_stop(struct vfe_device *vfe, u8 wm)
> +{
> +	wm = RDI_WM(wm); /* map to actual WM used (from wm=RDI index) */
> +	writel_relaxed(0, vfe->base + VFE_BUS_WM_CFG(wm));
> +}

vfe_wm_stop() as an example can/should live in a shared file.

As proof of concept code its fine to copy/paste between files but, to 
merge we need to get rid of any replicated code - introducing 
indirection/offsets as necessary.

> +static void vfe_wm_update(struct vfe_device *vfe, u8 wm, u64 addr,
> +			  struct vfe_line *line)
> +{
> +	wm = RDI_WM(wm); /* map to actual WM used (from wm=RDI index) */
> +	writel_relaxed((addr >> 8) & 0xFFFFFFFF, vfe->base + VFE_BUS_WM_IMAGE_ADDR(wm));
> +
> +	dev_dbg(vfe->camss->dev, "wm:%d, image buf addr:0x%llx\n",
> +		wm, addr);
> +}
> +
> +static void vfe_reg_update(struct vfe_device *vfe, enum vfe_line_id line_id)
> +{
> +	int port_id = line_id;
> +
> +	v4l2_subdev_notify(&vfe->line[line_id].subdev, NOTIFY_RUP, (void *)&port_id);
> +}
> +
> +static inline void vfe_reg_update_clear(struct vfe_device *vfe,
> +					enum vfe_line_id line_id)
> +{
> +	int port_id = line_id;
> +
> +	v4l2_subdev_notify(&vfe->line[line_id].subdev, NOTIFY_RUP_CLEAR, (void *)&port_id);
> +}

I'm not sure I quite understand why we need to use this API to clear 
registers inside of the address space of the same driver.

Is there not a much more direct way to write our _internal_ registers ?


> +static void vfe_enable_irq_common(struct vfe_device *vfe, enum vfe_line_id line_id)
> +{
> +	int port_id = line_id;
> +
> +	/* enable top BUS status IRQ */
> +	writel_relaxed(IRQ_MASK_0_BUS_TOP_IRQ,
> +				vfe->base + VFE_IRQ_MASK(0));
> +
> +	writel_relaxed(IRQ_MASK_1_BUS_TOP_IRQ(port_id),
> +				vfe->base + VFE_IRQ_MASK(1));
> +}
> +
> +/*
> + * vfe_isr - VFE module interrupt handler
> + * @irq: Interrupt line
> + * @dev: VFE device
> + *
> + * Return IRQ_HANDLED on success
> + */
> +static irqreturn_t vfe_isr(int irq, void *dev)
> +{
> +	struct vfe_device *vfe = dev;
> +	u32 status;
> +
> +	status = readl_relaxed(vfe->base + VFE_IRQ_STATUS(0));
> +	writel_relaxed(status, vfe->base + VFE_IRQ_CLEAR(0));
> +	writel_relaxed(IRQ_CMD_GLOBAL_CLEAR, vfe->base + VFE_IRQ_CMD);
> +
> +	if (status)
> +		dev_dbg(vfe->camss->dev, "Top Status_0:0x%x\n", status);
> +
> +	status = readl_relaxed(vfe->base + VFE_IRQ_STATUS(1));
> +	writel_relaxed(status, vfe->base + VFE_IRQ_CLEAR(1));
> +	writel_relaxed(IRQ_CMD_GLOBAL_CLEAR, vfe->base + VFE_IRQ_CMD);
> +
> +	if (status)
> +		dev_dbg(vfe->camss->dev, "Top Status_1:0x%x\n", status);
> +
> +	return IRQ_HANDLED;
> +}

Why is this ISR required ? What does it do ?

Does it actually run on your reference hardware ?

If the purpose of the ISR is just to clear the status registers, why 
even enable it ?

> +
> +/*
> + * vfe_halt - Trigger halt on VFE module and wait to complete
> + * @vfe: VFE device
> + *
> + * Return 0 on success or a negative error code otherwise
> + */
> +static int vfe_halt(struct vfe_device *vfe)
> +{
> +	/* rely on vfe_disable_output() to stop the VFE */
> +	return 0;
> +}
> +
> +static int vfe_get_output(struct vfe_line *line)
> +{
> +	struct vfe_device *vfe = to_vfe(line);
> +	struct vfe_output *output;
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&vfe->output_lock, flags);
> +
> +	output = &line->output;
> +	if (output->state > VFE_OUTPUT_RESERVED) {
> +		dev_err(vfe->camss->dev, "Output is running\n");
> +		goto error;
> +	}
> +
> +	output->wm_num = 1;
> +
> +	/* Correspondence between VFE line number and WM number.
> +	 * line 0 -> RDI 0, line 1 -> RDI1, line 2 -> RDI2, line 3 -> PIX/RDI3
> +	 * Note this 1:1 mapping will not work for PIX streams.
> +	 */
> +	output->wm_idx[0] = line->id;
> +	vfe->wm_output_map[line->id] = line->id;
> +
> +	output->drop_update_idx = 0;
> +
> +	spin_unlock_irqrestore(&vfe->output_lock, flags);
> +
> +	return 0;
> +
> +error:
> +	spin_unlock_irqrestore(&vfe->output_lock, flags);
> +	output->state = VFE_OUTPUT_OFF;
> +
> +	return -EINVAL;
> +}
> +
> +static int vfe_enable_output(struct vfe_line *line)
> +{
> +	struct vfe_device *vfe = to_vfe(line);
> +	struct vfe_output *output = &line->output;
> +	unsigned long flags;
> +	unsigned int i;
> +
> +	spin_lock_irqsave(&vfe->output_lock, flags);
> +
> +	vfe_reg_update_clear(vfe, line->id);
> +
> +	if (output->state > VFE_OUTPUT_RESERVED) {
> +		dev_err(vfe->camss->dev, "Output is not in reserved state %d\n",
> +			output->state);
> +		spin_unlock_irqrestore(&vfe->output_lock, flags);
> +		return -EINVAL;
> +	}
> +
> +	WARN_ON(output->gen2.active_num);
> +
> +	output->state = VFE_OUTPUT_ON;
> +
> +	output->sequence = 0;
> +
> +	vfe_wm_start(vfe, output->wm_idx[0], line);
> +
> +	for (i = 0; i < MAX_VFE_ACT_BUF; i++) {
> +		output->buf[i] = vfe_buf_get_pending(output);
> +		if (!output->buf[i])
> +			break;
> +		output->gen2.active_num++;
> +		vfe_wm_update(vfe, output->wm_idx[0], output->buf[i]->addr[0], line);
> +
> +		vfe_reg_update(vfe, line->id);
> +	}
> +
> +	spin_unlock_irqrestore(&vfe->output_lock, flags);
> +
> +	return 0;
> +}

So you'll see with the WIP code for x1e80100 which is I think the same 
VFE - no one generation less 680 - that this code is copy/pasted.

But there's again no good reason for that. Common code needs to be 
squashed down into one place.

---
bod

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