imx: mx6: add clock api for lcdif

Implement mxs_set_lcdclk, enable_lcdif_clock and enable_pll_video.
The three API can be used to configure lcdif related clock when
CONFIG_VIDEO_MXS enabled.

Signed-off-by: Peng Fan <Peng.Fan@freescale.com>
Cc: Stefano Babic <sbabic@denx.de>

2 files changed, 247 insertions, 0 deletions

diff --git a/arch/arm/cpu/armv7/mx6/clock.c b/arch/arm/cpu/armv7/mx6/clock.c
index 11efd12c9a7..67e0f3252f0 100644
--- a/arch/arm/cpu/armv7/mx6/clock.c
+++ b/arch/arm/cpu/armv7/mx6/clock.c
@@ -473,6 +473,251 @@ static u32 get_mmdc_ch0_clk(void)
 	}
 }
 
+#if defined(CONFIG_VIDEO_MXS)
+static int enable_pll_video(u32 pll_div, u32 pll_num, u32 pll_denom,
+			    u32 post_div)
+{
+	u32 reg = 0;
+	ulong start;
+
+	debug("pll5 div = %d, num = %d, denom = %d\n",
+	      pll_div, pll_num, pll_denom);
+
+	/* Power up PLL5 video */
+	writel(BM_ANADIG_PLL_VIDEO_POWERDOWN |
+	       BM_ANADIG_PLL_VIDEO_BYPASS |
+	       BM_ANADIG_PLL_VIDEO_DIV_SELECT |
+	       BM_ANADIG_PLL_VIDEO_POST_DIV_SELECT,
+	       &imx_ccm->analog_pll_video_clr);
+
+	/* Set div, num and denom */
+	switch (post_div) {
+	case 1:
+		writel(BF_ANADIG_PLL_VIDEO_DIV_SELECT(pll_div) |
+		       BF_ANADIG_PLL_VIDEO_POST_DIV_SELECT(0x2),
+		       &imx_ccm->analog_pll_video_set);
+		break;
+	case 2:
+		writel(BF_ANADIG_PLL_VIDEO_DIV_SELECT(pll_div) |
+		       BF_ANADIG_PLL_VIDEO_POST_DIV_SELECT(0x1),
+		       &imx_ccm->analog_pll_video_set);
+		break;
+	case 4:
+		writel(BF_ANADIG_PLL_VIDEO_DIV_SELECT(pll_div) |
+		       BF_ANADIG_PLL_VIDEO_POST_DIV_SELECT(0x0),
+		       &imx_ccm->analog_pll_video_set);
+		break;
+	default:
+		puts("Wrong test_div!\n");
+		return -EINVAL;
+	}
+
+	writel(BF_ANADIG_PLL_VIDEO_NUM_A(pll_num),
+	       &imx_ccm->analog_pll_video_num);
+	writel(BF_ANADIG_PLL_VIDEO_DENOM_B(pll_denom),
+	       &imx_ccm->analog_pll_video_denom);
+
+	/* Wait PLL5 lock */
+	start = get_timer(0);	/* Get current timestamp */
+
+	do {
+		reg = readl(&imx_ccm->analog_pll_video);
+		if (reg & BM_ANADIG_PLL_VIDEO_LOCK) {
+			/* Enable PLL out */
+			writel(BM_ANADIG_PLL_VIDEO_ENABLE,
+			       &imx_ccm->analog_pll_video_set);
+			return 0;
+		}
+	} while (get_timer(0) < (start + 10)); /* Wait 10ms */
+
+	puts("Lock PLL5 timeout\n");
+
+	return -ETIME;
+}
+
+/*
+ * 24M--> PLL_VIDEO -> LCDIFx_PRED -> LCDIFx_PODF -> LCD
+ *
+ * 'freq' using KHz as unit, see driver/video/mxsfb.c.
+ */
+void mxs_set_lcdclk(u32 base_addr, u32 freq)
+{
+	u32 reg = 0;
+	u32 hck = MXC_HCLK / 1000;
+	/* DIV_SELECT ranges from 27 to 54 */
+	u32 min = hck * 27;
+	u32 max = hck * 54;
+	u32 temp, best = 0;
+	u32 i, j, max_pred = 8, max_postd = 8, pred = 1, postd = 1;
+	u32 pll_div, pll_num, pll_denom, post_div = 1;
+
+	debug("mxs_set_lcdclk, freq = %dKHz\n", freq);
+
+	if ((!is_cpu_type(MXC_CPU_MX6SX)) && !is_cpu_type(MXC_CPU_MX6UL)) {
+		debug("This chip not support lcd!\n");
+		return;
+	}
+
+	if (base_addr == LCDIF1_BASE_ADDR) {
+		reg = readl(&imx_ccm->cscdr2);
+		/* Can't change clocks when clock not from pre-mux */
+		if ((reg & MXC_CCM_CSCDR2_LCDIF1_CLK_SEL_MASK) != 0)
+			return;
+	}
+
+	if (is_cpu_type(MXC_CPU_MX6SX)) {
+		reg = readl(&imx_ccm->cscdr2);
+		/* Can't change clocks when clock not from pre-mux */
+		if ((reg & MXC_CCM_CSCDR2_LCDIF2_CLK_SEL_MASK) != 0)
+			return;
+	}
+
+	temp = freq * max_pred * max_postd;
+	if (temp > max) {
+		puts("Please decrease freq, too large!\n");
+		return;
+	}
+	if (temp < min) {
+		/*
+		 * Register: PLL_VIDEO
+		 * Bit Field: POST_DIV_SELECT
+		 * 00 — Divide by 4.
+		 * 01 — Divide by 2.
+		 * 10 — Divide by 1.
+		 * 11 — Reserved
+		 * No need to check post_div(1)
+		 */
+		for (post_div = 2; post_div <= 4; post_div <<= 1) {
+			if ((temp * post_div) > min) {
+				freq *= post_div;
+				break;
+			}
+		}
+
+		if (post_div > 4) {
+			printf("Fail to set rate to %dkhz", freq);
+			return;
+		}
+	}
+
+	/* Choose the best pred and postd to match freq for lcd */
+	for (i = 1; i <= max_pred; i++) {
+		for (j = 1; j <= max_postd; j++) {
+			temp = freq * i * j;
+			if (temp > max || temp < min)
+				continue;
+			if (best == 0 || temp < best) {
+				best = temp;
+				pred = i;
+				postd = j;
+			}
+		}
+	}
+
+	if (best == 0) {
+		printf("Fail to set rate to %dKHz", freq);
+		return;
+	}
+
+	debug("best %d, pred = %d, postd = %d\n", best, pred, postd);
+
+	pll_div = best / hck;
+	pll_denom = 1000000;
+	pll_num = (best - hck * pll_div) * pll_denom / hck;
+
+	/*
+	 *                                  pll_num
+	 *             (24MHz * (pll_div + --------- ))
+	 *                                 pll_denom
+	 *freq KHz =  --------------------------------
+	 *             post_div * pred * postd * 1000
+	 */
+
+	if (base_addr == LCDIF1_BASE_ADDR) {
+		if (enable_pll_video(pll_div, pll_num, pll_denom, post_div))
+			return;
+
+		/* Select pre-lcd clock to PLL5 and set pre divider */
+		clrsetbits_le32(&imx_ccm->cscdr2,
+				MXC_CCM_CSCDR2_LCDIF1_PRED_SEL_MASK |
+				MXC_CCM_CSCDR2_LCDIF1_PRE_DIV_MASK,
+				(0x2 << MXC_CCM_CSCDR2_LCDIF1_PRED_SEL_OFFSET) |
+				((pred - 1) <<
+				 MXC_CCM_CSCDR2_LCDIF1_PRE_DIV_OFFSET));
+
+		/* Set the post divider */
+		clrsetbits_le32(&imx_ccm->cbcmr,
+				MXC_CCM_CBCMR_LCDIF1_PODF_MASK,
+				((postd - 1) <<
+				 MXC_CCM_CBCMR_LCDIF1_PODF_OFFSET));
+	} else if (is_cpu_type(MXC_CPU_MX6SX)) {
+		/* Setting LCDIF2 for i.MX6SX */
+		if (enable_pll_video(pll_div, pll_num, pll_denom, post_div))
+			return;
+
+		/* Select pre-lcd clock to PLL5 and set pre divider */
+		clrsetbits_le32(&imx_ccm->cscdr2,
+				MXC_CCM_CSCDR2_LCDIF2_PRED_SEL_MASK |
+				MXC_CCM_CSCDR2_LCDIF2_PRE_DIV_MASK,
+				(0x2 << MXC_CCM_CSCDR2_LCDIF2_PRED_SEL_OFFSET) |
+				((pred - 1) <<
+				 MXC_CCM_CSCDR2_LCDIF2_PRE_DIV_OFFSET));
+
+		/* Set the post divider */
+		clrsetbits_le32(&imx_ccm->cscmr1,
+				MXC_CCM_CSCMR1_LCDIF2_PODF_MASK,
+				((postd - 1) <<
+				 MXC_CCM_CSCMR1_LCDIF2_PODF_OFFSET));
+	}
+}
+
+int enable_lcdif_clock(u32 base_addr)
+{
+	u32 reg = 0;
+	u32 lcdif_clk_sel_mask, lcdif_ccgr3_mask;
+
+	if (is_cpu_type(MXC_CPU_MX6SX)) {
+		if ((base_addr == LCDIF1_BASE_ADDR) ||
+		    (base_addr == LCDIF2_BASE_ADDR)) {
+			puts("Wrong LCD interface!\n");
+			return -EINVAL;
+		}
+		/* Set to pre-mux clock at default */
+		lcdif_clk_sel_mask = (base_addr == LCDIF2_BASE_ADDR) ?
+			MXC_CCM_CSCDR2_LCDIF2_CLK_SEL_MASK :
+			MXC_CCM_CSCDR2_LCDIF1_CLK_SEL_MASK;
+		lcdif_ccgr3_mask = (base_addr == LCDIF2_BASE_ADDR) ?
+			(MXC_CCM_CCGR3_LCDIF2_PIX_MASK |
+			 MXC_CCM_CCGR3_DISP_AXI_MASK) :
+			(MXC_CCM_CCGR3_LCDIF1_PIX_MASK |
+			 MXC_CCM_CCGR3_DISP_AXI_MASK);
+	} else if (is_cpu_type(MXC_CPU_MX6UL)) {
+		if (base_addr != LCDIF1_BASE_ADDR) {
+			puts("Wrong LCD interface!\n");
+			return -EINVAL;
+		}
+		/* Set to pre-mux clock at default */
+		lcdif_clk_sel_mask = MXC_CCM_CSCDR2_LCDIF1_CLK_SEL_MASK;
+		lcdif_ccgr3_mask =  MXC_CCM_CCGR3_LCDIF1_PIX_MASK;
+	} else {
+		return 0;
+	}
+
+	reg = readl(&imx_ccm->cscdr2);
+	reg &= ~lcdif_clk_sel_mask;
+	writel(reg, &imx_ccm->cscdr2);
+
+	/* Enable the LCDIF pix clock */
+	reg = readl(&imx_ccm->CCGR3);
+	reg |= lcdif_ccgr3_mask;
+	writel(reg, &imx_ccm->CCGR3);
+
+	reg = readl(&imx_ccm->CCGR2);
+	reg |= MXC_CCM_CCGR2_LCD_MASK;
+	writel(reg, &imx_ccm->CCGR2);
+}
+#endif
+
 #ifdef CONFIG_FSL_QSPI
 /* qspi_num can be from 0 - 1 */
 void enable_qspi_clk(int qspi_num)
diff --git a/arch/arm/include/asm/arch-mx6/clock.h b/arch/arm/include/asm/arch-mx6/clock.h
index 2b220d6f8f9..14505239e85 100644
--- a/arch/arm/include/asm/arch-mx6/clock.h
+++ b/arch/arm/include/asm/arch-mx6/clock.h
@@ -66,6 +66,8 @@ int enable_spi_clk(unsigned char enable, unsigned spi_num);
 void enable_ipu_clock(void);
 int enable_fec_anatop_clock(int fec_id, enum enet_freq freq);
 void enable_enet_clk(unsigned char enable);
+int enable_lcdif_clock(u32 base_addr);
 void enable_qspi_clk(int qspi_num);
 void enable_thermal_clk(void);
+void mxs_set_lcdclk(u32 base_addr, u32 freq);
 #endif /* __ASM_ARCH_CLOCK_H */