[PATCH 2/4] i.MX21/27: don't enable lcd bus clocks too early

Daniel Mierswa d.mierswa at phytec.de
Thu Jan 17 01:32:57 EST 2013


On the MX27 based board phycard-i.MX27 the display won't properly
come up.
Before removing imx-regs.h and the code that sets the register
in the i.MX video driver, the PCCR registers were set _after_
the screen start (LSSAR) was set.
This restores that old behaviour and makes the display come up
properly again.
I did not have a chance to test this on any other i.MX27 or i.MX21
hardware though I assume that the "old" order is required there
too.

Signed-off-by: Daniel Mierswa <d.mierswa at phytec.de>
---
 arch/arm/mach-imx/clk-imx21.c | 13 +++++++++++--
 arch/arm/mach-imx/clk-imx27.c | 14 +++++++++-----
 drivers/video/imx.c           | 40 +++++++++++++++++++++++++++++++++-------
 3 files changed, 53 insertions(+), 14 deletions(-)

diff --git a/arch/arm/mach-imx/clk-imx21.c b/arch/arm/mach-imx/clk-imx21.c
index 784951d..6e91424 100644
--- a/arch/arm/mach-imx/clk-imx21.c
+++ b/arch/arm/mach-imx/clk-imx21.c
@@ -89,7 +89,8 @@
 
 enum imx21_clks {
 	ckil, ckih, fpm, mpll_sel, spll_sel, mpll, spll, fclk, hclk, ipg, per1,
-	per2, per3, per4, usb_div, nfc_div, lcdc_per_gate, clk_max
+	per2, per3, per4, usb_div, nfc_div, lcdc_per_gate, lcdc_ahb_gate,
+	lcdc_ipg_gate, clk_max
 };
 
 static struct clk *clks[clk_max];
@@ -116,7 +117,7 @@ static int imx21_ccm_probe(struct device_d *dev)
 			PCCR0_CSPI1_EN | PCCR0_CSPI2_EN | PCCR0_SDHC1_EN |
 			PCCR0_SDHC2_EN | PCCR0_GPIO_EN | PCCR0_I2C_EN | PCCR0_DMA_EN |
 			PCCR0_USBOTG_EN | PCCR0_NFC_EN | PCCR0_PERCLK4_EN |
-			PCCR0_HCLK_USBOTG_EN | PCCR0_HCLK_LCDC_EN | PCCR0_HCLK_DMA_EN,
+			PCCR0_HCLK_USBOTG_EN | PCCR0_HCLK_DMA_EN,
 			base + CCM_PCCR0);
 
 	writel(PCCR1_CSPI3_EN | PCCR1_WDT_EN | PCCR1_GPT1_EN | PCCR1_GPT2_EN |
@@ -143,6 +144,12 @@ static int imx21_ccm_probe(struct device_d *dev)
 	clks[usb_div] = imx_clk_divider("usb_div", "spll", base + CCM_CSCR, 26, 3);
 	clks[nfc_div] = imx_clk_divider("nfc_div", "ipg", base + CCM_PCDR0, 12, 4);
 	clks[lcdc_per_gate] = imx_clk_gate("lcdc_per_gate", "per3", base + CCM_PCCR0, 18);
+	clks[lcdc_ahb_gate] = imx_clk_gate("lcdc_ahb_gate", "ahb", base + CCM_PCCR0, 26);
+	/*
+	 * i.MX21 doesn't have an IPG clock for the LCD. To avoid even more conditionals
+	 * in the framebuffer code, provide a dummy clock.
+	 */
+	clks[lcdc_ipg_gate] = clk_fixed("dummy", 0);
 
 	clkdev_add_physbase(clks[per1], MX21_GPT1_BASE_ADDR, NULL);
 	clkdev_add_physbase(clks[per1], MX21_GPT2_BASE_ADDR, NULL);
@@ -158,6 +165,8 @@ static int imx21_ccm_probe(struct device_d *dev)
 	clkdev_add_physbase(clks[ipg], MX21_SDHC1_BASE_ADDR, NULL);
 	clkdev_add_physbase(clks[ipg], MX21_SDHC2_BASE_ADDR, NULL);
 	clkdev_add_physbase(clks[lcdc_per_gate], MX21_LCDC_BASE_ADDR, NULL);
+	clkdev_add_physbase(clks[lcdc_ahb_gate], MX21_LCDC_BASE_ADDR, "ahb");
+	clkdev_add_physbase(clks[lcdc_ipg_gate], MX21_LCDC_BASE_ADDR, "ipg");
 
 	return 0;
 }
diff --git a/arch/arm/mach-imx/clk-imx27.c b/arch/arm/mach-imx/clk-imx27.c
index 222d2a6..958495e 100644
--- a/arch/arm/mach-imx/clk-imx27.c
+++ b/arch/arm/mach-imx/clk-imx27.c
@@ -93,7 +93,7 @@
 enum mx27_clks {
 	dummy, ckih, ckil, mpll, spll, mpll_main2, ahb, ipg, nfc_div, per1_div,
 	per2_div, per3_div, per4_div, usb_div, cpu_sel,	clko_sel, cpu_div, clko_div,
-	clko_en, lcdc_per_gate, clk_max
+	clko_en, lcdc_per_gate, lcdc_ahb_gate, lcdc_ipg_gate, clk_max
 };
 
 static struct clk *clks[clk_max];
@@ -136,7 +136,7 @@ static int imx27_ccm_probe(struct device_d *dev)
 	base = dev_request_mem_region(dev, 0);
 
 	writel(PCCR0_SDHC3_EN | PCCR0_SDHC2_EN | PCCR0_SDHC1_EN |
-			PCCR0_PWM_EN | PCCR0_KPP_EN | PCCR0_LCDC_EN | PCCR0_IIM_EN |
+			PCCR0_PWM_EN | PCCR0_KPP_EN | PCCR0_IIM_EN |
 			PCCR0_I2C2_EN | PCCR0_I2C1_EN | PCCR0_GPT6_EN | PCCR0_GPT5_EN |
 			PCCR0_GPT4_EN | PCCR0_GPT3_EN | PCCR0_GPT2_EN | PCCR0_GPT1_EN |
 			PCCR0_GPIO_EN | PCCR0_FEC_EN | PCCR0_CSPI3_EN | PCCR0_CSPI2_EN |
@@ -144,9 +144,9 @@ static int imx27_ccm_probe(struct device_d *dev)
 			base + CCM_PCCR0);
 
 	writel(PCCR1_NFC_BAUDEN | PCCR1_PERCLK4_EN | PCCR1_PERCLK2_EN | PCCR1_PERCLK1_EN |
-			PCCR1_HCLK_USB | PCCR1_HCLK_LCDC | PCCR1_HCLK_FEC | PCCR1_HCLK_EMI |
-			PCCR1_WDT_EN | PCCR1_USB_EN | PCCR1_UART6_EN | PCCR1_UART5_EN |
-			PCCR1_UART4_EN | PCCR1_UART3_EN | PCCR1_UART2_EN | PCCR1_UART1_EN,
+			PCCR1_HCLK_USB | PCCR1_HCLK_FEC | PCCR1_HCLK_EMI | PCCR1_WDT_EN |
+			PCCR1_USB_EN | PCCR1_UART6_EN | PCCR1_UART5_EN | PCCR1_UART4_EN |
+			PCCR1_UART3_EN | PCCR1_UART2_EN | PCCR1_UART1_EN,
 			base + CCM_PCCR1);
 
 	clks[dummy] = clk_fixed("dummy", 0);
@@ -180,6 +180,8 @@ static int imx27_ccm_probe(struct device_d *dev)
 		clks[cpu_div] = imx_clk_divider("cpu_div", "cpu_sel", base + CCM_CSCR, 13, 3);
 	clks[clko_div] = imx_clk_divider("clko_div", "clko_sel", base + CCM_PCDR0, 22, 3);
 	clks[lcdc_per_gate] = imx_clk_gate("lcdc_per_gate", "per3_div", base + CCM_PCCR1, 7);
+	clks[lcdc_ahb_gate] = imx_clk_gate("lcdc_ahb_gate", "ahb", base + CCM_PCCR1, 15);
+	clks[lcdc_ipg_gate] = imx_clk_gate("lcdc_ipg_gate", "ipg", base + CCM_PCCR0, 14);
 
 	clkdev_add_physbase(clks[per1_div], MX27_GPT1_BASE_ADDR, NULL);
 	clkdev_add_physbase(clks[per1_div], MX27_GPT2_BASE_ADDR, NULL);
@@ -202,6 +204,8 @@ static int imx27_ccm_probe(struct device_d *dev)
 	clkdev_add_physbase(clks[per2_div], MX27_SDHC2_BASE_ADDR, NULL);
 	clkdev_add_physbase(clks[per2_div], MX27_SDHC3_BASE_ADDR, NULL);
 	clkdev_add_physbase(clks[lcdc_per_gate], MX27_LCDC_BASE_ADDR, NULL);
+	clkdev_add_physbase(clks[lcdc_ahb_gate], MX27_LCDC_BASE_ADDR, "ahb");
+	clkdev_add_physbase(clks[lcdc_ipg_gate], MX27_LCDC_BASE_ADDR, "ipg");
 	clkdev_add_physbase(clks[ipg], MX27_FEC_BASE_ADDR, NULL);
 
 	return 0;
diff --git a/drivers/video/imx.c b/drivers/video/imx.c
index 8381690..54fb700 100644
--- a/drivers/video/imx.c
+++ b/drivers/video/imx.c
@@ -138,7 +138,13 @@ struct imxfb_rgb {
 
 struct imxfb_info {
 	void __iomem		*regs;
-	struct clk		*clk;
+
+#if defined(CONFIG_ARCH_IMX21) || defined(CONFIG_ARCH_IMX27)
+	struct clk		*ahb_clk;
+	struct clk		*ipg_clk;
+#endif
+
+	struct clk		*per_clk;
 
 	u_int			pcr;
 	u_int			pwmr;
@@ -252,7 +258,12 @@ static void imxfb_enable_controller(struct fb_info *info)
 
 	writel(RMCR_LCDC_EN, fbi->regs + LCDC_RMCR);
 
-	clk_enable(fbi->clk);
+#if defined(CONFIG_ARCH_IMX21) || defined(CONFIG_ARCH_IMX27)
+	clk_enable(fbi->ahb_clk);
+	clk_enable(fbi->ipg_clk);
+#endif
+
+	clk_enable(fbi->per_clk);
 
 	if (fbi->enable)
 		fbi->enable(1);
@@ -267,7 +278,12 @@ static void imxfb_disable_controller(struct fb_info *info)
 
 	writel(0, fbi->regs + LCDC_RMCR);
 
-	clk_disable(fbi->clk);
+	clk_disable(fbi->per_clk);
+
+#if defined(CONFIG_ARCH_IMX21) || defined(CONFIG_ARCH_IMX27)
+	clk_disable(fbi->ipg_clk);
+	clk_disable(fbi->ahb_clk);
+#endif
 }
 
 static void set_reg_overlay(struct fb_info *overlay)
@@ -335,7 +351,7 @@ static int imxfb_activate_var(struct fb_info *info)
 	writel(readl(fbi->regs + LCDC_CPOS) & ~(CPOS_CC0 | CPOS_CC1),
 		fbi->regs + LCDC_CPOS);
 
-	lcd_clk = clk_get_rate(fbi->clk);
+	lcd_clk = clk_get_rate(fbi->per_clk);
 
 	tmp = mode->pixclock * (unsigned long long)lcd_clk;
 
@@ -549,9 +565,19 @@ static int imxfb_probe(struct device_d *dev)
 	fbi = xzalloc(sizeof(*fbi));
 	info = &fbi->info;
 
-	fbi->clk = clk_get(dev, NULL);
-	if (IS_ERR(fbi->clk))
-		return PTR_ERR(fbi->clk);
+	fbi->per_clk = clk_get(dev, NULL);
+	if (IS_ERR(fbi->per_clk))
+		return PTR_ERR(fbi->per_clk);
+
+#if defined(CONFIG_ARCH_IMX21) || defined(CONFIG_ARCH_IMX27)
+	fbi->ahb_clk = clk_get(dev, "ahb");
+	if (IS_ERR(fbi->ahb_clk))
+		return PTR_ERR(fbi->ahb_clk);
+
+	fbi->ipg_clk = clk_get(dev, "ipg");
+	if (IS_ERR(fbi->ipg_clk))
+		return PTR_ERR(fbi->ipg_clk);
+#endif
 
 	fbi->mode = pdata->mode;
 	fbi->regs = dev_request_mem_region(dev, 0);
-- 
1.8.1




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