diff options
| -rw-r--r-- | drivers/gpu/drm/mxsfb/mxsfb_crtc.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c index 1144e0c9e894..0abe77675b76 100644 --- a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c +++ b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c @@ -35,6 +35,13 @@ #include "mxsfb_drv.h" #include "mxsfb_regs.h" +#define MXS_SET_ADDR 0x4 +#define MXS_CLR_ADDR 0x8 +#define MODULE_CLKGATE BIT(30) +#define MODULE_SFTRST BIT(31) +/* 1 second delay should be plenty of time for block reset */ +#define RESET_TIMEOUT 1000000 + static u32 set_hsync_pulse_width(struct mxsfb_drm_private *mxsfb, u32 val) { return (val & mxsfb->devdata->hs_wdth_mask) << @@ -159,6 +166,36 @@ static void mxsfb_disable_controller(struct mxsfb_drm_private *mxsfb) clk_disable_unprepare(mxsfb->clk_disp_axi); } +/* + * Clear the bit and poll it cleared. This is usually called with + * a reset address and mask being either SFTRST(bit 31) or CLKGATE + * (bit 30). + */ +static int clear_poll_bit(void __iomem *addr, u32 mask) +{ + u32 reg; + + writel(mask, addr + MXS_CLR_ADDR); + return readl_poll_timeout(addr, reg, !(reg & mask), 0, RESET_TIMEOUT); +} + +static int mxsfb_reset_block(void __iomem *reset_addr) +{ + int ret; + + ret = clear_poll_bit(reset_addr, MODULE_SFTRST); + if (ret) + return ret; + + writel(MODULE_CLKGATE, reset_addr + MXS_CLR_ADDR); + + ret = clear_poll_bit(reset_addr, MODULE_SFTRST); + if (ret) + return ret; + + return clear_poll_bit(reset_addr, MODULE_CLKGATE); +} + static void mxsfb_crtc_mode_set_nofb(struct mxsfb_drm_private *mxsfb) { struct drm_display_mode *m = &mxsfb->pipe.crtc.state->adjusted_mode; @@ -173,6 +210,11 @@ static void mxsfb_crtc_mode_set_nofb(struct mxsfb_drm_private *mxsfb) */ mxsfb_enable_axi_clk(mxsfb); + /* Mandatory eLCDIF reset as per the Reference Manual */ + err = mxsfb_reset_block(mxsfb->base); + if (err) + return; + /* Clear the FIFOs */ writel(CTRL1_FIFO_CLEAR, mxsfb->base + LCDC_CTRL1 + REG_SET); |