Re: [PATCH v5 06/10] drm/mediatek: add dsi interrupt control

[CK Hu <ck.hu@mediatek.com>]

Hi, YT:

On Thu, 2016-07-28 at 17:28 +0800, YT Shen wrote:
> From: shaoming chen <shaoming.chen@mediatek.com>
> 
> add dsi interrupt control
> 
> Signed-off-by: shaoming chen <shaoming.chen@mediatek.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_dsi.c |   92 ++++++++++++++++++++++++++++++++++++
>  1 file changed, 92 insertions(+)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index a9cf5a1..553443a 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> @@ -18,6 +18,7 @@
>  #include <drm/drm_panel.h>
>  #include <linux/clk.h>
>  #include <linux/component.h>
> +#include <linux/irq.h>
>  #include <linux/of.h>
>  #include <linux/of_platform.h>
>  #include <linux/of_graph.h>
> @@ -29,6 +30,17 @@
>  
>  #define DSI_START		0x00
>  
> +#define DSI_INTEN		0x08
> +
> +#define DSI_INTSTA		0x0c
> +#define LPRX_RD_RDY_INT_FLAG		BIT(0)
> +#define CMD_DONE_INT_FLAG		BIT(1)
> +#define TE_RDY_INT_FLAG			BIT(2)
> +#define VM_DONE_INT_FLAG		BIT(3)
> +#define EXT_TE_RDY_INT_FLAG		BIT(4)
> +#define DSI_INT_ALL_BITS		0x7f
> +#define DSI_BUSY			BIT(31)
> +
>  #define DSI_CON_CTRL		0x10
>  #define DSI_RESET			BIT(0)
>  #define DSI_EN				BIT(1)
> @@ -71,6 +83,9 @@
>  
>  #define DSI_HSTX_CKL_WC		0x64
>  
> +#define DSI_RACK		0x84
> +#define RACK				BIT(0)
> +
>  #define DSI_PHY_LCCON		0x104
>  #define LC_HS_TX_EN			BIT(0)
>  #define LC_ULPM_EN			BIT(1)
> @@ -131,8 +146,13 @@ struct mtk_dsi {
>  	struct videomode vm;
>  	int refcount;
>  	bool enabled;
> +	int irq_data;
>  };
>  
> +static wait_queue_head_t _dsi_cmd_done_wait_queue;
> +static wait_queue_head_t _dsi_dcs_read_wait_queue;
> +static wait_queue_head_t _dsi_wait_vm_done_queue;

I think for difference irq status we can use only one wait queue. So
multiple client wait on the same wait queue, but each client has
different wake up condition.

> +
>  static inline struct mtk_dsi *encoder_to_dsi(struct drm_encoder *e)
>  {
>  	return container_of(e, struct mtk_dsi, encoder);
> @@ -437,6 +457,55 @@ static void mtk_dsi_start(struct mtk_dsi *dsi)
>  	writel(1, dsi->regs + DSI_START);
>  }
>  
> +static void mtk_dsi_set_interrupt_enable(struct mtk_dsi *dsi)
> +{
> +	u32 inten = DSI_INT_ALL_BITS;
> +
> +	if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO)
> +		inten &= ~(TE_RDY_INT_FLAG | EXT_TE_RDY_INT_FLAG);
> +
> +	writel(inten, dsi->regs + DSI_INTEN);
> +}
> +
> +static void mtk_dsi_irq_wakeup(struct mtk_dsi *dsi, u32 irq_bit)
> +{
> +	dsi->irq_data |= irq_bit;
> +}
> +
> +static irqreturn_t mtk_dsi_irq(int irq, void *dev_id)
> +{
> +	struct mtk_dsi *dsi = dev_id;
> +
> +	u32 status, tmp;
> +
> +	status = readl(dsi->regs + DSI_INTSTA);
> +
> +	if (status & LPRX_RD_RDY_INT_FLAG) {
> +		do {
> +			mtk_dsi_mask(dsi, DSI_RACK, RACK, RACK);
> +			tmp = readl(dsi->regs + DSI_INTSTA);
> +		} while (tmp & DSI_BUSY);
> +
> +		mtk_dsi_mask(dsi, DSI_INTSTA, LPRX_RD_RDY_INT_FLAG, 0);
> +		mtk_dsi_irq_wakeup(dsi, LPRX_RD_RDY_INT_FLAG);
> +		wake_up_interruptible(&_dsi_dcs_read_wait_queue);
> +	}
> +
> +	if (status & CMD_DONE_INT_FLAG) {
> +		mtk_dsi_mask(dsi, DSI_INTSTA, CMD_DONE_INT_FLAG, 0);
> +		mtk_dsi_irq_wakeup(dsi, CMD_DONE_INT_FLAG);
> +		wake_up_interruptible(&_dsi_cmd_done_wait_queue);
> +	}
> +
> +	if (status & VM_DONE_INT_FLAG) {
> +		mtk_dsi_mask(dsi, DSI_INTSTA, VM_DONE_INT_FLAG, 0);
> +		mtk_dsi_irq_wakeup(dsi, VM_DONE_INT_FLAG);
> +		wake_up_interruptible(&_dsi_wait_vm_done_queue);
> +	}

I think these three part can be merged into one.
u32 deal_status = LPRX_RD_RDY_INT_FLAG | CMD_DONE_INT_FLAG |
VM_DONE_INT_FLAG;
if (status & deal_status) {
    mtk_dsi_mask(dsi, DSI_INTSTA, deal_status, 0);
    mtk_dsi_irq_wakeup(dsi, status & deal_status);
    wake_up_interruptible(&_dsi_irq_wait_queue);
}

Otherwise, why enable DSI_INT_ALL_BITS, but deal only
LPRX_RD_RDY_INT_FLAG, CMD_DONE_INT_FLAG, and VM_DONE_INT_FLAG?

> +
> +	return IRQ_HANDLED;
> +}
> +
>  static void mtk_dsi_poweroff(struct mtk_dsi *dsi)
>  {
>  	if (WARN_ON(dsi->refcount == 0))
> @@ -485,6 +554,7 @@ static void mtk_output_dsi_enable(struct mtk_dsi *dsi)
>  
>  	mtk_dsi_ps_control_vact(dsi);
>  	mtk_dsi_config_vdo_timing(dsi);
> +	mtk_dsi_set_interrupt_enable(dsi);
>  
>  	mtk_dsi_set_mode(dsi);
>  	mtk_dsi_clk_hs_mode(dsi, 1);
> @@ -804,6 +874,7 @@ static int mtk_dsi_probe(struct platform_device *pdev)
>  	struct device *dev = &pdev->dev;
>  	struct device_node *remote_node, *endpoint;
>  	struct resource *regs;
> +	int irq_num;
>  	int comp_id;
>  	int ret;
>  
> @@ -880,8 +951,29 @@ static int mtk_dsi_probe(struct platform_device *pdev)
>  		return ret;
>  	}
>  
> +	irq_num = platform_get_irq(pdev, 0);
> +	if (irq_num < 0) {
> +		dev_err(&pdev->dev, "failed to request dsi irq resource\n");
> +		return -EPROBE_DEFER;
> +	}
> +
> +	irq_set_status_flags(irq_num, IRQ_TYPE_LEVEL_LOW);
> +	ret = devm_request_irq(&pdev->dev, irq_num, mtk_dsi_irq,
> +			       IRQF_TRIGGER_LOW, dev_name(&pdev->dev), dsi);
> +	if (ret) {
> +		dev_err(&pdev->dev, "failed to request mediatek dsi irq\n");
> +		return -EPROBE_DEFER;
> +	}
> +
> +	dsi->irq_data = 0;
> +	dev_info(dev, "dsi irq num is 0x%x\n", irq_num);
> +
>  	platform_set_drvdata(pdev, dsi);
>  
> +	init_waitqueue_head(&_dsi_cmd_done_wait_queue);
> +	init_waitqueue_head(&_dsi_dcs_read_wait_queue);
> +	init_waitqueue_head(&_dsi_wait_vm_done_queue);
> +
>  	return component_add(&pdev->dev, &mtk_dsi_component_ops);
>  }
>  

Regards,
CK