OMAP3 clock: introduce DPLL4 Jtype
DPLL4 for 3630 introduces a changed block called j type dpll, requiring
special divisor bits and additional reg fields. To allow for silicons to
use this, this is introduced as a flag and is enabled for 3630 silicon.
OMAP4 also has j type dpll for usb.
Tested with 3630 ZOOM3 and OMAP3430 ZOOM2
Signed-off-by: Richard Woodruff <r-woodruff2@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Vishwanath BS <Vishwanath.bs@ti.com>
[paul@pwsan.com: added some comments; updated copyrights and credits; fixed
some style issues]
Signed-off-by: Paul Walmsley <paul@pwsan.com>
diff --git a/arch/arm/mach-omap2/dpll3xxx.c b/arch/arm/mach-omap2/dpll3xxx.c
index 68268cd..417c3ca 100644
--- a/arch/arm/mach-omap2/dpll3xxx.c
+++ b/arch/arm/mach-omap2/dpll3xxx.c
@@ -1,11 +1,14 @@
/*
* OMAP3/4 - specific DPLL control functions
*
- * Copyright (C) 2009 Texas Instruments, Inc.
- * Copyright (C) 2009 Nokia Corporation
+ * Copyright (C) 2009-2010 Texas Instruments, Inc.
+ * Copyright (C) 2009-2010 Nokia Corporation
*
* Written by Paul Walmsley
- * Testing and integration fixes by Jouni Högander
+ * Testing and integration fixes by Jouni Högander
+ *
+ * 36xx support added by Vishwanath BS, Richard Woodruff, and Nishanth
+ * Menon
*
* Parts of this code are based on code written by
* Richard Woodruff, Tony Lindgren, Tuukka Tikkanen, Karthik Dasu
@@ -225,6 +228,47 @@
return 0;
}
+/**
+ * lookup_dco_sddiv - Set j-type DPLL4 compensation variables
+ * @clk: pointer to a DPLL struct clk
+ * @dco: digital control oscillator selector
+ * @sd_div: target sigma-delta divider
+ * @m: DPLL multiplier to set
+ * @n: DPLL divider to set
+ *
+ * See 36xx TRM section 3.5.3.3.3.2 "Type B DPLL (Low-Jitter)"
+ *
+ * XXX This code is not needed for 3430/AM35xx; can it be optimized
+ * out in non-multi-OMAP builds for those chips?
+ */
+static void lookup_dco_sddiv(struct clk *clk, u8 *dco, u8 *sd_div, u16 m,
+ u8 n)
+{
+ unsigned long fint, clkinp, sd; /* watch out for overflow */
+ int mod1, mod2;
+
+ clkinp = clk->parent->rate;
+ fint = (clkinp / n) * m;
+
+ if (fint < 1000000000)
+ *dco = 2;
+ else
+ *dco = 4;
+ /*
+ * target sigma-delta to near 250MHz
+ * sd = ceil[(m/(n+1)) * (clkinp_MHz / 250)]
+ */
+ clkinp /= 100000; /* shift from MHz to 10*Hz for 38.4 and 19.2 */
+ mod1 = (clkinp * m) % (250 * n);
+ sd = (clkinp * m) / (250 * n);
+ mod2 = sd % 10;
+ sd /= 10;
+
+ if (mod1 || mod2)
+ sd++;
+ *sd_div = sd;
+}
+
/*
* _omap3_noncore_dpll_program - set non-core DPLL M,N values directly
* @clk: struct clk * of DPLL to set
@@ -259,6 +303,21 @@
v &= ~(dd->mult_mask | dd->div1_mask);
v |= m << __ffs(dd->mult_mask);
v |= (n - 1) << __ffs(dd->div1_mask);
+
+ /*
+ * XXX This code is not needed for 3430/AM35XX; can it be optimized
+ * out in non-multi-OMAP builds for those chips?
+ */
+ if ((dd->flags & DPLL_J_TYPE) && !(dd->flags & DPLL_NO_DCO_SEL)) {
+ u8 dco, sd_div;
+ lookup_dco_sddiv(clk, &dco, &sd_div, m, n);
+ /* XXX This probably will need revision for OMAP4 */
+ v &= ~(OMAP3630_PERIPH_DPLL_DCO_SEL_MASK
+ | OMAP3630_PERIPH_DPLL_SD_DIV_MASK);
+ v |= dco << __ffs(OMAP3630_PERIPH_DPLL_DCO_SEL_MASK);
+ v |= sd_div << __ffs(OMAP3630_PERIPH_DPLL_SD_DIV_MASK);
+ }
+
__raw_writel(v, dd->mult_div1_reg);
/* We let the clock framework set the other output dividers later */
@@ -536,7 +595,7 @@
v = __raw_readl(dd->control_reg) & dd->enable_mask;
v >>= __ffs(dd->enable_mask);
- if (v != OMAP3XXX_EN_DPLL_LOCKED)
+ if ((v != OMAP3XXX_EN_DPLL_LOCKED) || (dd->flags & DPLL_J_TYPE))
rate = clk->parent->rate;
else
rate = clk->parent->rate * 2;