[ARM] OMAP2/3: Add non-CORE DPLL rate set code and M, N programming

Add non-CORE DPLL rate set code and M,N programming for OMAP3.
Connect it to OMAP34xx DPLLs 1, 2, 4, 5 via the clock framework.

You may see some warnings on rate sets from the freqsel code.  The
table that TI presented in the 3430 TRM Rev F does not cover Fint <
750000, which definitely occurs in practice.  However, the lack of this
freqsel case does not appear to impair the DPLL rate change.

linux-omap source commit is 689fe67c6d1ad8f52f7f7b139a3274b79bf3e784.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 136 insertions, 1 deletions

diff --git a/arch/arm/mach-omap2/clock34xx.c b/arch/arm/mach-omap2/clock34xx.c
index 245a7b9b560c..943ac63fc6f8 100644
--- a/arch/arm/mach-omap2/clock34xx.c
+++ b/arch/arm/mach-omap2/clock34xx.c
@@ -340,6 +340,42 @@ static int _omap3_wait_dpll_status(struct clk *clk, u8 state)
 	return ret;
 }
 
+/* From 3430 TRM ES2 4.7.6.2 */
+static u16 _omap3_dpll_compute_freqsel(struct clk *clk, u8 n)
+{
+	unsigned long fint;
+	u16 f = 0;
+
+	fint = clk->parent->rate / (n + 1);
+
+	pr_debug("clock: fint is %lu\n", fint);
+
+	if (fint >= 750000 && fint <= 1000000)
+		f = 0x3;
+	else if (fint > 1000000 && fint <= 1250000)
+		f = 0x4;
+	else if (fint > 1250000 && fint <= 1500000)
+		f = 0x5;
+	else if (fint > 1500000 && fint <= 1750000)
+		f = 0x6;
+	else if (fint > 1750000 && fint <= 2100000)
+		f = 0x7;
+	else if (fint > 7500000 && fint <= 10000000)
+		f = 0xB;
+	else if (fint > 10000000 && fint <= 12500000)
+		f = 0xC;
+	else if (fint > 12500000 && fint <= 15000000)
+		f = 0xD;
+	else if (fint > 15000000 && fint <= 17500000)
+		f = 0xE;
+	else if (fint > 17500000 && fint <= 21000000)
+		f = 0xF;
+	else
+		pr_debug("clock: unknown freqsel setting for %d\n", n);
+
+	return f;
+}
+
 /* Non-CORE DPLL (e.g., DPLLs that do not control SDRC) clock functions */
 
 /*
@@ -476,7 +512,7 @@ static int omap3_noncore_dpll_enable(struct clk *clk)
 	if (clk == &dpll3_ck)
 		return -EINVAL;
 
-	if (clk->parent->rate == clk_get_rate(clk))
+	if (clk->parent->rate == omap2_get_dpll_rate(clk))
 		r = _omap3_noncore_dpll_bypass(clk);
 	else
 		r = _omap3_noncore_dpll_lock(clk);
@@ -506,11 +542,110 @@ static void omap3_noncore_dpll_disable(struct clk *clk)
 	_omap3_noncore_dpll_stop(clk);
 }
 
+
+/* Non-CORE DPLL rate set code */
+
+/*
+ * omap3_noncore_dpll_program - set non-core DPLL M,N values directly
+ * @clk: struct clk * of DPLL to set
+ * @m: DPLL multiplier to set
+ * @n: DPLL divider to set
+ * @freqsel: FREQSEL value to set
+ *
+ * Program the DPLL with the supplied M, N values, and wait for the DPLL to
+ * lock..  Returns -EINVAL upon error, or 0 upon success.
+ */
+static int omap3_noncore_dpll_program(struct clk *clk, u16 m, u8 n, u16 freqsel)
+{
+	struct dpll_data *dd = clk->dpll_data;
+	u32 v;
+
+	/* 3430 ES2 TRM: 4.7.6.9 DPLL Programming Sequence */
+	_omap3_noncore_dpll_bypass(clk);
+
+	v = __raw_readl(dd->mult_div1_reg);
+	v &= ~(dd->mult_mask | dd->div1_mask);
+
+	/* Set mult (M), div1 (N), freqsel */
+	v |= m << __ffs(dd->mult_mask);
+	v |= n << __ffs(dd->div1_mask);
+	v |= freqsel << __ffs(dd->freqsel_mask);
+
+	__raw_writel(v, dd->mult_div1_reg);
+
+	/* We let the clock framework set the other output dividers later */
+
+	/* REVISIT: Set ramp-up delay? */
+
+	_omap3_noncore_dpll_lock(clk);
+
+	return 0;
+}
+
+/**
+ * omap3_noncore_dpll_set_rate - set non-core DPLL rate
+ * @clk: struct clk * of DPLL to set
+ * @rate: rounded target rate
+ *
+ * Program the DPLL with the rounded target rate.  Returns -EINVAL upon
+ * error, or 0 upon success.
+ */
+static int omap3_noncore_dpll_set_rate(struct clk *clk, unsigned long rate)
+{
+	u16 freqsel;
+	struct dpll_data *dd;
+
+	if (!clk || !rate)
+		return -EINVAL;
+
+	dd = clk->dpll_data;
+	if (!dd)
+		return -EINVAL;
+
+	if (rate == omap2_get_dpll_rate(clk))
+		return 0;
+
+	if (dd->last_rounded_rate != rate)
+		omap2_dpll_round_rate(clk, rate);
+
+	if (dd->last_rounded_rate == 0)
+		return -EINVAL;
+
+	freqsel = _omap3_dpll_compute_freqsel(clk, dd->last_rounded_n);
+	if (!freqsel)
+		WARN_ON(1);
+
+	omap3_noncore_dpll_program(clk, dd->last_rounded_m, dd->last_rounded_n,
+				   freqsel);
+
+	omap3_dpll_recalc(clk);
+
+	return 0;
+}
+
+static int omap3_dpll4_set_rate(struct clk *clk, unsigned long rate)
+{
+	/*
+	 * According to the 12-5 CDP code from TI, "Limitation 2.5"
+	 * on 3430ES1 prevents us from changing DPLL multipliers or dividers
+	 * on DPLL4.
+	 */
+	if (omap_rev() == OMAP3430_REV_ES1_0) {
+		printk(KERN_ERR "clock: DPLL4 cannot change rate due to "
+		       "silicon 'Limitation 2.5' on 3430ES1.\n");
+		return -EINVAL;
+	}
+	return omap3_noncore_dpll_set_rate(clk, rate);
+}
+
 static const struct clkops clkops_noncore_dpll_ops = {
 	.enable		= &omap3_noncore_dpll_enable,
 	.disable	= &omap3_noncore_dpll_disable,
 };
 
+/* DPLL autoidle read/set code */
+
+
 /**
  * omap3_dpll_autoidle_read - read a DPLL's autoidle bits
  * @clk: struct clk * of the DPLL to read