Re: [PATCH v4 5/8] drm/mediatek: add dsi interrupt control
From: CK Hu
Date: Tue Jul 19 2016 - 01:39:45 EST
Hi, YT:
Some comments inline.
On Fri, 2016-07-15 at 18:07 +0800, YT Shen wrote:
> From: shaoming chen <shaoming.chen@xxxxxxxxxxxx>
>
> add dsi interrupt control
>
> Signed-off-by: shaoming chen <shaoming.chen@xxxxxxxxxxxx>
> ---
> drivers/gpu/drm/mediatek/mtk_dsi.c | 130 ++++++++++++++++++++++++++++++++++++
> 1 file changed, 130 insertions(+)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index 2d808e5..de5ad7f 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>
> @@ -32,6 +33,13 @@
>
> #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 DSI_BUSY BIT(31)
Why need LPRX_RD_RDY_INT_FLAG, CMD_DONE_INT_FLAG, and DSI_BUSY? Maybe
these three should be moved to other patch.
> +
> #define DSI_CON_CTRL 0x10
> #define DSI_RESET BIT(0)
> #define DSI_EN BIT(1)
> @@ -74,6 +82,9 @@
>
> #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)
> @@ -134,6 +145,18 @@ struct mtk_dsi {
> struct videomode vm;
> int refcount;
> bool enabled;
> + int irq_num, irq_data;
> +};
> +
> +enum {
> + DSI_INT_SLEEPOUT_DONE_FLAG = BIT(6),
> + DSI_INT_VM_CMD_DONE_FLAG = BIT(5),
> + DSI_INT_EXT_TE_RDY_FLAG = BIT(4),
> + DSI_INT_VM_DONE_FLAG = BIT(3),
> + DSI_INT_TE_RDY_FLAG = BIT(2),
> + DSI_INT_CMD_DONE_FLAG = BIT(1),
> + DSI_INT_LPRX_RD_RDY_FLAG = BIT(0),
> + DSI_INT_ALL_BITS = (0x7f)
> };
I think you should use '#define' instead of 'enum'. The code would be
like below, and these definition should be moved to after DSI_INTEN or
DSI_INTSTA.
#define DSI_INT_LPRX_RD_RDY_FLAG BIT(0)
#define DSI_INT_CMD_DONE_FLAG BIT(1)
#define DSI_INT_TE_RDY_FLAG BIT(2)
#define DSI_INT_VM_DONE_FLAG BIT(3)
#define DSI_INT_EXT_TE_RDY_FLAG BIT(4)
#define DSI_INT_VM_CMD_DONE_FLAG BIT(5)
#define DSI_INT_SLEEPOUT_DONE_FLAG BIT(6)
#define DSI_INT_ALL_BITS (DSI_INT_LPRX_RD_RDY_FLAG | \
DSI_INT_CMD_DONE_FLAG | \
DSI_INT_TE_RDY_FLAG | \
DSI_INT_VM_DONE_FLAG | \
DSI_INT_EXT_TE_RDY_FLAG | \
DSI_INT_VM_CMD_DONE_FLAG | \
DSI_INT_SLEEPOUT_DONE_FLAG)
>
> static inline struct mtk_dsi *encoder_to_dsi(struct drm_encoder *e)
> @@ -440,6 +463,94 @@ 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 &= ~(DSI_INT_TE_RDY_FLAG | DSI_INT_EXT_TE_RDY_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 & DSI_INT_LPRX_RD_RDY_FLAG) {
> + /* write clear RD_RDY interrupt */
> + /* write clear RD_RDY interrupt must be before DSI_RACK */
> + /* because CMD_DONE will raise after DSI_RACK, */
> + /* so write clear RD_RDY after that will clear CMD_DONE too */
> + do {
> + /* send read ACK */
> + mtk_dsi_mask(dsi, DSI_RACK, RACK, RACK);
> + tmp = readl(dsi->regs + DSI_INTSTA);
> + } while (tmp & DSI_BUSY);
> +
> + mtk_dsi_mask(dsi, DSI_INTSTA, DSI_INT_LPRX_RD_RDY_FLAG, 0);
> + mtk_dsi_irq_wakeup(dsi, DSI_INT_LPRX_RD_RDY_FLAG);
> + }
> +
> + if (status & DSI_INT_CMD_DONE_FLAG) {
> + mtk_dsi_mask(dsi, DSI_INTSTA, DSI_INT_CMD_DONE_FLAG, 0);
> + mtk_dsi_irq_wakeup(dsi, DSI_INT_CMD_DONE_FLAG);
> + }
> +
> + if (status & DSI_INT_TE_RDY_FLAG) {
> + mtk_dsi_mask(dsi, DSI_INTSTA, DSI_INT_TE_RDY_FLAG, 0);
> + mtk_dsi_irq_wakeup(dsi, DSI_INT_TE_RDY_FLAG);
> + }
> +
> + if (status & DSI_INT_VM_DONE_FLAG) {
> + mtk_dsi_mask(dsi, DSI_INTSTA, DSI_INT_VM_DONE_FLAG, 0);
> + mtk_dsi_irq_wakeup(dsi, DSI_INT_VM_DONE_FLAG);
> + }
> +
> + if (status & DSI_INT_EXT_TE_RDY_FLAG) {
> + mtk_dsi_mask(dsi, DSI_INTSTA, DSI_INT_EXT_TE_RDY_FLAG, 0);
> + mtk_dsi_irq_wakeup(dsi, DSI_INT_EXT_TE_RDY_FLAG);
> + }
> +
> + if (status & DSI_INT_VM_CMD_DONE_FLAG) {
> + mtk_dsi_mask(dsi, DSI_INTSTA, DSI_INT_VM_CMD_DONE_FLAG, 0);
> + mtk_dsi_irq_wakeup(dsi, DSI_INT_VM_CMD_DONE_FLAG);
> + }
> +
> + if (status & DSI_INT_SLEEPOUT_DONE_FLAG) {
> + mtk_dsi_mask(dsi, DSI_INTSTA, DSI_INT_SLEEPOUT_DONE_FLAG, 0);
> + mtk_dsi_irq_wakeup(dsi, DSI_INT_SLEEPOUT_DONE_FLAG);
> + }
All these 'if' statement do the same thing and I think these could be
merge as:
status = readl(dsi->regs + DSI_INTSTA) & DSI_INT_ALL_BITS);
if (status) {
mtk_dsi_mask(dsi, DSI_INTSTA, status, 0);
mtk_dsi_irq_wakeup(dsi, status);
}
> +
> + return IRQ_HANDLED;
> +}
> +
> +static s32 mtk_dsi_wait_for_irq_timeout(struct mtk_dsi *dsi, u32 irq_bit,
> + u32 timeout_ms)
> +{
> + while (timeout_ms--) {
> + if (dsi->irq_data & irq_bit) {
> + dsi->irq_data &= ~irq_bit;
> + return 0;
> + }
> +
> + usleep_range(1000, 1100);
> + }
I think it's better to use wait_event() or something else. Polling with
sleep could not react immediately.
> +
> + dsi->irq_data = 0;
Why clear all bit after wait one bit timeout?
> +
> + return -1;
> +}
> +
> static void mtk_dsi_poweroff(struct mtk_dsi *dsi)
> {
> if (WARN_ON(dsi->refcount == 0))
> @@ -488,6 +599,7 @@ static void mtk_output_dsi_enable(struct mtk_dsi *dsi)
>
> dsi_ps_control_vact(dsi);
> dsi_config_vdo_timing(dsi);
> + mtk_dsi_set_interrupt_enable(dsi);
>
> dsi_set_mode(dsi);
> dsi_clk_hs_mode(dsi, 1);
> @@ -883,6 +995,24 @@ static int mtk_dsi_probe(struct platform_device *pdev)
> return ret;
> }
>
> + dsi->irq_num = platform_get_irq(pdev, 0);
You use irq_num only in this function, why keep it in dsi structure?
> + if (dsi->irq_num < 0) {
> + dev_err(&pdev->dev, "failed to request dsi irq resource\n");
> + ret = dsi->irq_num;
> + return -EPROBE_DEFER;
> + }
> +
> + irq_set_status_flags(dsi->irq_num, IRQ_TYPE_LEVEL_LOW);
> + ret = devm_request_irq(&pdev->dev, dsi->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", dsi->irq_num);
> +
> platform_set_drvdata(pdev, dsi);
>
> return component_add(&pdev->dev, &mtk_dsi_component_ops);
Regards,
CK