OMAPDSS: HDMI: PLL changes for OMAP5

Add a features struct to differentiate between the HDMI PLLs on OMAP4
and OMAP5. The OMAP5 PLL is more sensitive when it comes to locking.  We
need to ensure that the DCO freq isn't too low for lower pixel clocks.

Modify the PLL computation slightly to ensure the HDMI PLL locks for lower
frequencies. This will be later replaced by a more complex computation
which makes sure all the PLL constraints are met.
Signed-off-by: Archit Taneja <archit@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/video/fbdev/omap2/dss/hdmi_pll.c

@@ -23,6 +23,18 @@
 #define HDMI_DEFAULT_REGN 16
 #define HDMI_DEFAULT_REGM2 1
 
+struct hdmi_pll_features {
+	bool sys_reset;
+	/* this is a hack, need to replace it with a better computation of M2 */
+	bool bound_dcofreq;
+	unsigned long fint_min, fint_max;
+	u16 regm_max;
+	unsigned long dcofreq_low_min, dcofreq_low_max;
+	unsigned long dcofreq_high_min, dcofreq_high_max;
+};
+
+static const struct hdmi_pll_features *pll_feat;
+
 void hdmi_pll_dump(struct hdmi_pll_data *pll, struct seq_file *s)
 {
 #define DUMPPLL(r) seq_printf(s, "%-35s %08x\n", #r,\
@@ -57,7 +69,11 @@ void hdmi_pll_compute(struct hdmi_pll_data *pll, unsigned long clkin, int phy)
 
 	refclk = clkin / pi->regn;
 
-	pi->regm2 = HDMI_DEFAULT_REGM2;
+	/* temorary hack to make sure DCO freq isn't calculated too low */
+	if (pll_feat->bound_dcofreq && phy <= 65000)
+		pi->regm2 = 3;
+	else
+		pi->regm2 = HDMI_DEFAULT_REGM2;
 
 	/*
 	 * multiplier is pixel_clk/ref_clk
@@ -154,7 +170,7 @@ static int hdmi_pll_config(struct hdmi_pll_data *pll)
 static int hdmi_pll_reset(struct hdmi_pll_data *pll)
 {
 	/* SYSRESET  controlled by power FSM */
-	REG_FLD_MOD(pll->base, PLLCTRL_PLL_CONTROL, 0x0, 3, 3);
+	REG_FLD_MOD(pll->base, PLLCTRL_PLL_CONTROL, pll_feat->sys_reset, 3, 3);
 
 	/* READ 0x0 reset is in progress */
 	if (hdmi_wait_for_bit_change(pll->base, PLLCTRL_PLL_STATUS, 0, 0, 1)
@@ -197,11 +213,72 @@ void hdmi_pll_disable(struct hdmi_pll_data *pll, struct hdmi_wp_data *wp)
 #define PLL_OFFSET	0x200
 #define PLL_SIZE	0x100
 
+static const struct hdmi_pll_features omap44xx_pll_feats = {
+	.sys_reset		=	false,
+	.bound_dcofreq		=	false,
+	.fint_min		=	500000,
+	.fint_max		=	2500000,
+	.regm_max		=	4095,
+	.dcofreq_low_min	=	500000000,
+	.dcofreq_low_max	=	1000000000,
+	.dcofreq_high_min	=	1000000000,
+	.dcofreq_high_max	=	2000000000,
+};
+
+static const struct hdmi_pll_features omap54xx_pll_feats = {
+	.sys_reset		=	true,
+	.bound_dcofreq		=	true,
+	.fint_min		=	620000,
+	.fint_max		=	2500000,
+	.regm_max		=	2046,
+	.dcofreq_low_min	=	750000000,
+	.dcofreq_low_max	=	1500000000,
+	.dcofreq_high_min	=	1250000000,
+	.dcofreq_high_max	=	2500000000UL,
+};
+
+static int hdmi_pll_init_features(struct platform_device *pdev)
+{
+	struct hdmi_pll_features *dst;
+	const struct hdmi_pll_features *src;
+
+	dst = devm_kzalloc(&pdev->dev, sizeof(*dst), GFP_KERNEL);
+	if (!dst) {
+		dev_err(&pdev->dev, "Failed to allocate HDMI PHY Features\n");
+		return -ENOMEM;
+	}
+
+	switch (omapdss_get_version()) {
+	case OMAPDSS_VER_OMAP4430_ES1:
+	case OMAPDSS_VER_OMAP4430_ES2:
+	case OMAPDSS_VER_OMAP4:
+		src = &omap44xx_pll_feats;
+		break;
+
+	case OMAPDSS_VER_OMAP5:
+		src = &omap54xx_pll_feats;
+		break;
+
+	default:
+		return -ENODEV;
+	}
+
+	memcpy(dst, src, sizeof(*dst));
+	pll_feat = dst;
+
+	return 0;
+}
+
 int hdmi_pll_init(struct platform_device *pdev, struct hdmi_pll_data *pll)
 {
+	int r;
 	struct resource *res;
 	struct resource temp_res;
 
+	r = hdmi_pll_init_features(pdev);
+	if (r)
+		return r;
+
 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "pll");
 	if (!res) {
 		DSSDBG("can't get PLL mem resource by name\n");