video: da8xx-fb: Interrupt configuration of revised LCDC IP

An upcoming SoC of TI comes with an LCD controller which is an updated
version of that found on TI's DA850 SoC. The da8xx-fb driver can support
this LCD with some enhancements.
This patch adds support for updated interrupt configuration on the new
SoC.
1) Registers for setting and clearing interrupts are different.
2) Raw and masked status registers are different.
The updates have been tested on an emulation platform for new features
and the patch has been tested on DA850 platform to make sure nothing
existing breaks.

Signed-off-by: Manjunathappa, Prakash <prakash.pm@ti.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

drivers/video/da8xx-fb.c

@@ -35,6 +35,9 @@
 
 #define DRIVER_NAME "da8xx_lcdc"
 
+#define LCD_VERSION_1	1
+#define LCD_VERSION_2	2
+
 /* LCD Status Register */
 #define LCD_END_OF_FRAME1		BIT(9)
 #define LCD_END_OF_FRAME0		BIT(8)
@@ -49,7 +52,9 @@
 #define LCD_DMA_BURST_4			0x2
 #define LCD_DMA_BURST_8			0x3
 #define LCD_DMA_BURST_16		0x4
-#define LCD_END_OF_FRAME_INT_ENA	BIT(2)
+#define LCD_V1_END_OF_FRAME_INT_ENA	BIT(2)
+#define LCD_V2_END_OF_FRAME0_INT_ENA	BIT(8)
+#define LCD_V2_END_OF_FRAME1_INT_ENA	BIT(9)
 #define LCD_DUAL_FRAME_BUFFER_ENABLE	BIT(0)
 
 /* LCD Control Register */
@@ -65,12 +70,18 @@
 #define LCD_MONO_8BIT_MODE		BIT(9)
 #define LCD_RASTER_ORDER		BIT(8)
 #define LCD_TFT_MODE			BIT(7)
-#define LCD_UNDERFLOW_INT_ENA		BIT(6)
-#define LCD_PL_ENABLE			BIT(4)
+#define LCD_V1_UNDERFLOW_INT_ENA	BIT(6)
+#define LCD_V2_UNDERFLOW_INT_ENA	BIT(5)
+#define LCD_V1_PL_INT_ENA		BIT(4)
+#define LCD_V2_PL_INT_ENA		BIT(6)
 #define LCD_MONOCHROME_MODE		BIT(1)
 #define LCD_RASTER_ENABLE		BIT(0)
 #define LCD_TFT_ALT_ENABLE		BIT(23)
 #define LCD_STN_565_ENABLE		BIT(24)
+#define LCD_V2_DMA_CLK_EN		BIT(2)
+#define LCD_V2_LIDD_CLK_EN		BIT(1)
+#define LCD_V2_CORE_CLK_EN		BIT(0)
+#define LCD_V2_LPP_B10			26
 
 /* LCD Raster Timing 2 Register */
 #define LCD_AC_BIAS_TRANSITIONS_PER_INT(x)	((x) << 16)
@@ -82,6 +93,7 @@
 #define LCD_INVERT_FRAME_CLOCK			BIT(20)
 
 /* LCD Block */
+#define  LCD_PID_REG				0x0
 #define  LCD_CTRL_REG				0x4
 #define  LCD_STAT_REG				0x8
 #define  LCD_RASTER_CTRL_REG			0x28
@@ -94,6 +106,17 @@
 #define  LCD_DMA_FRM_BUF_BASE_ADDR_1_REG	0x4C
 #define  LCD_DMA_FRM_BUF_CEILING_ADDR_1_REG	0x50
 
+/* Interrupt Registers available only in Version 2 */
+#define  LCD_RAW_STAT_REG			0x58
+#define  LCD_MASKED_STAT_REG			0x5c
+#define  LCD_INT_ENABLE_SET_REG			0x60
+#define  LCD_INT_ENABLE_CLR_REG			0x64
+#define  LCD_END_OF_INT_IND_REG			0x68
+
+/* Clock registers available only on Version 2 */
+#define  LCD_CLK_ENABLE_REG			0x6c
+#define  LCD_CLK_RESET_REG			0x70
+
 #define LCD_NUM_BUFFERS	2
 
 #define WSI_TIMEOUT	50
@@ -105,6 +128,8 @@
 
 static resource_size_t da8xx_fb_reg_base;
 static struct resource *lcdc_regs;
+static unsigned int lcd_revision;
+static irq_handler_t lcdc_irq_handler;
 
 static inline unsigned int lcdc_read(unsigned int addr)
 {
@@ -240,6 +265,7 @@ static void lcd_blit(int load_mode, struct da8xx_fb_par *par)
 	u32 end;
 	u32 reg_ras;
 	u32 reg_dma;
+	u32 reg_int;
 
 	/* init reg to clear PLM (loading mode) fields */
 	reg_ras = lcdc_read(LCD_RASTER_CTRL_REG);
@@ -252,7 +278,14 @@ static void lcd_blit(int load_mode, struct da8xx_fb_par *par)
 		end      = par->dma_end;
 
 		reg_ras |= LCD_PALETTE_LOAD_MODE(DATA_ONLY);
-		reg_dma |= LCD_END_OF_FRAME_INT_ENA;
+		if (lcd_revision == LCD_VERSION_1) {
+			reg_dma |= LCD_V1_END_OF_FRAME_INT_ENA;
+		} else {
+			reg_int = lcdc_read(LCD_INT_ENABLE_SET_REG) |
+				LCD_V2_END_OF_FRAME0_INT_ENA |
+				LCD_V2_END_OF_FRAME1_INT_ENA;
+			lcdc_write(reg_int, LCD_INT_ENABLE_SET_REG);
+		}
 		reg_dma |= LCD_DUAL_FRAME_BUFFER_ENABLE;
 
 		lcdc_write(start, LCD_DMA_FRM_BUF_BASE_ADDR_0_REG);
@@ -264,7 +297,14 @@ static void lcd_blit(int load_mode, struct da8xx_fb_par *par)
 		end      = start + par->palette_sz - 1;
 
 		reg_ras |= LCD_PALETTE_LOAD_MODE(PALETTE_ONLY);
-		reg_ras |= LCD_PL_ENABLE;
+
+		if (lcd_revision == LCD_VERSION_1) {
+			reg_ras |= LCD_V1_PL_INT_ENA;
+		} else {
+			reg_int = lcdc_read(LCD_INT_ENABLE_SET_REG) |
+				LCD_V2_PL_INT_ENA;
+			lcdc_write(reg_int, LCD_INT_ENABLE_SET_REG);
+		}
 
 		lcdc_write(start, LCD_DMA_FRM_BUF_BASE_ADDR_0_REG);
 		lcdc_write(end, LCD_DMA_FRM_BUF_CEILING_ADDR_0_REG);
@@ -348,6 +388,7 @@ static void lcd_cfg_vertical_sync(int back_porch, int pulse_width,
 static int lcd_cfg_display(const struct lcd_ctrl_config *cfg)
 {
 	u32 reg;
+	u32 reg_int;
 
 	reg = lcdc_read(LCD_RASTER_CTRL_REG) & ~(LCD_TFT_MODE |
 						LCD_MONO_8BIT_MODE |
@@ -375,7 +416,13 @@ static int lcd_cfg_display(const struct lcd_ctrl_config *cfg)
 	}
 
 	/* enable additional interrupts here */
-	reg |= LCD_UNDERFLOW_INT_ENA;
+	if (lcd_revision == LCD_VERSION_1) {
+		reg |= LCD_V1_UNDERFLOW_INT_ENA;
+	} else {
+		reg_int = lcdc_read(LCD_INT_ENABLE_SET_REG) |
+			LCD_V2_UNDERFLOW_INT_ENA;
+		lcdc_write(reg_int, LCD_INT_ENABLE_SET_REG);
+	}
 
 	lcdc_write(reg, LCD_RASTER_CTRL_REG);
 
@@ -511,6 +558,9 @@ static void lcd_reset(struct da8xx_fb_par *par)
 	/* DMA has to be disabled */
 	lcdc_write(0, LCD_DMA_CTRL_REG);
 	lcdc_write(0, LCD_RASTER_CTRL_REG);
+
+	if (lcd_revision == LCD_VERSION_2)
+		lcdc_write(0, LCD_INT_ENABLE_SET_REG);
 }
 
 static void lcd_calc_clk_divider(struct da8xx_fb_par *par)
@@ -523,6 +573,11 @@ static void lcd_calc_clk_divider(struct da8xx_fb_par *par)
 	/* Configure the LCD clock divisor. */
 	lcdc_write(LCD_CLK_DIVISOR(div) |
 			(LCD_RASTER_MODE & 0x1), LCD_CTRL_REG);
+
+	if (lcd_revision == LCD_VERSION_2)
+		lcdc_write(LCD_V2_DMA_CLK_EN | LCD_V2_LIDD_CLK_EN |
+				LCD_V2_CORE_CLK_EN, LCD_CLK_ENABLE_REG);
+
 }
 
 static int lcd_init(struct da8xx_fb_par *par, const struct lcd_ctrl_config *cfg,
@@ -583,7 +638,63 @@ static int lcd_init(struct da8xx_fb_par *par, const struct lcd_ctrl_config *cfg,
 	return 0;
 }
 
-static irqreturn_t lcdc_irq_handler(int irq, void *arg)
+/* IRQ handler for version 2 of LCDC */
+static irqreturn_t lcdc_irq_handler_rev02(int irq, void *arg)
+{
+	struct da8xx_fb_par *par = arg;
+	u32 stat = lcdc_read(LCD_MASKED_STAT_REG);
+	u32 reg_int;
+
+	if ((stat & LCD_SYNC_LOST) && (stat & LCD_FIFO_UNDERFLOW)) {
+		lcd_disable_raster();
+		lcdc_write(stat, LCD_MASKED_STAT_REG);
+		lcd_enable_raster();
+	} else if (stat & LCD_PL_LOAD_DONE) {
+		/*
+		 * Must disable raster before changing state of any control bit.
+		 * And also must be disabled before clearing the PL loading
+		 * interrupt via the following write to the status register. If
+		 * this is done after then one gets multiple PL done interrupts.
+		 */
+		lcd_disable_raster();
+
+		lcdc_write(stat, LCD_MASKED_STAT_REG);
+
+		/* Disable PL completion inerrupt */
+		reg_int = lcdc_read(LCD_INT_ENABLE_CLR_REG) |
+		       (LCD_V2_PL_INT_ENA);
+		lcdc_write(reg_int, LCD_INT_ENABLE_CLR_REG);
+
+		/* Setup and start data loading mode */
+		lcd_blit(LOAD_DATA, par);
+	} else {
+		lcdc_write(stat, LCD_MASKED_STAT_REG);
+
+		if (stat & LCD_END_OF_FRAME0) {
+			lcdc_write(par->dma_start,
+				   LCD_DMA_FRM_BUF_BASE_ADDR_0_REG);
+			lcdc_write(par->dma_end,
+				   LCD_DMA_FRM_BUF_CEILING_ADDR_0_REG);
+			par->vsync_flag = 1;
+			wake_up_interruptible(&par->vsync_wait);
+		}
+
+		if (stat & LCD_END_OF_FRAME1) {
+			lcdc_write(par->dma_start,
+				   LCD_DMA_FRM_BUF_BASE_ADDR_1_REG);
+			lcdc_write(par->dma_end,
+				   LCD_DMA_FRM_BUF_CEILING_ADDR_1_REG);
+			par->vsync_flag = 1;
+			wake_up_interruptible(&par->vsync_wait);
+		}
+	}
+
+	lcdc_write(0, LCD_END_OF_INT_IND_REG);
+	return IRQ_HANDLED;
+}
+
+/* IRQ handler for version 1 LCDC */
+static irqreturn_t lcdc_irq_handler_rev01(int irq, void *arg)
 {
 	struct da8xx_fb_par *par = arg;
 	u32 stat = lcdc_read(LCD_STAT_REG);
@@ -606,7 +717,7 @@ static irqreturn_t lcdc_irq_handler(int irq, void *arg)
 
 		/* Disable PL completion inerrupt */
 		reg_ras  = lcdc_read(LCD_RASTER_CTRL_REG);
-		reg_ras &= ~LCD_PL_ENABLE;
+		reg_ras &= ~LCD_V1_PL_INT_ENA;
 		lcdc_write(reg_ras, LCD_RASTER_CTRL_REG);
 
 		/* Setup and start data loading mode */
@@ -945,6 +1056,22 @@ static int __devinit fb_probe(struct platform_device *device)
 	if (ret)
 		goto err_clk_put;
 
+	/* Determine LCD IP Version */
+	switch (lcdc_read(LCD_PID_REG)) {
+	case 0x4C100102:
+		lcd_revision = LCD_VERSION_1;
+		break;
+	case 0x4F200800:
+		lcd_revision = LCD_VERSION_2;
+		break;
+	default:
+		dev_warn(&device->dev, "Unknown PID Reg value 0x%x, "
+				"defaulting to LCD revision 1\n",
+				lcdc_read(LCD_PID_REG));
+		lcd_revision = LCD_VERSION_1;
+		break;
+	}
+
 	for (i = 0, lcdc_info = known_lcd_panels;
 		i < ARRAY_SIZE(known_lcd_panels);
 		i++, lcdc_info++) {
@@ -1085,7 +1212,13 @@ static int __devinit fb_probe(struct platform_device *device)
 	}
 #endif
 
-	ret = request_irq(par->irq, lcdc_irq_handler, 0, DRIVER_NAME, par);
+	if (lcd_revision == LCD_VERSION_1)
+		lcdc_irq_handler = lcdc_irq_handler_rev01;
+	else
+		lcdc_irq_handler = lcdc_irq_handler_rev02;
+
+	ret = request_irq(par->irq, lcdc_irq_handler, 0,
+			DRIVER_NAME, par);
 	if (ret)
 		goto irq_freq;
 	return 0;