#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/clk.h>
-#include <linux/bitops.h>
#include <linux/io.h>
+#include <linux/bitops.h>
#include <mach/clock.h>
#include <mach/clockdomain.h>
#define DPLL_MIN_DIVIDER 1
/* Possible error results from _dpll_test_mult */
-#define DPLL_MULT_UNDERFLOW (1 << 0)
+#define DPLL_MULT_UNDERFLOW -1
/*
* Scale factor to mitigate roundoff errors in DPLL rate rounding.
#define DPLL_ROUNDING_VAL ((DPLL_SCALE_BASE / 2) * \
(DPLL_SCALE_FACTOR / DPLL_SCALE_BASE))
-/* Some OMAP2xxx CM_CLKSEL_PLL.ST_CORE_CLK bits - for omap2_get_dpll_rate() */
-#define ST_CORE_CLK_REF 0x1
-#define ST_CORE_CLK_32K 0x3
+/* DPLL valid Fint frequency band limits - from 34xx TRM Section 4.7.6.2 */
+#define DPLL_FINT_BAND1_MIN 750000
+#define DPLL_FINT_BAND1_MAX 2100000
+#define DPLL_FINT_BAND2_MIN 7500000
+#define DPLL_FINT_BAND2_MAX 21000000
+
+/* _dpll_test_fint() return codes */
+#define DPLL_FINT_UNDERFLOW -1
+#define DPLL_FINT_INVALID -2
/* Bitmask to isolate the register type of clk.enable_reg */
#define PRCM_REGTYPE_MASK 0xf0
cm_write_mod_reg(v, clk->prcm_mod, reg_offset);
}
+/*
+ * _dpll_test_fint - test whether an Fint value is valid for the DPLL
+ * @clk: DPLL struct clk to test
+ * @n: divider value (N) to test
+ *
+ * Tests whether a particular divider @n will result in a valid DPLL
+ * internal clock frequency Fint. See the 34xx TRM 4.7.6.2 "DPLL Jitter
+ * Correction". Returns 0 if OK, -1 if the enclosing loop can terminate
+ * (assuming that it is counting N upwards), or -2 if the enclosing loop
+ * should skip to the next iteration (again assuming N is increasing).
+ */
+static int _dpll_test_fint(struct clk *clk, u8 n)
+{
+ struct dpll_data *dd;
+ long fint;
+ int ret = 0;
+
+ dd = clk->dpll_data;
+
+ /* DPLL divider must result in a valid jitter correction val */
+ fint = clk->parent->rate / (n + 1);
+ if (fint < DPLL_FINT_BAND1_MIN) {
+
+ pr_debug("rejecting n=%d due to Fint failure, "
+ "lowering max_divider\n", n);
+ dd->max_divider = n;
+ ret = DPLL_FINT_UNDERFLOW;
+
+ } else if (fint > DPLL_FINT_BAND1_MAX &&
+ fint < DPLL_FINT_BAND2_MIN) {
+
+ pr_debug("rejecting n=%d due to Fint failure\n", n);
+ ret = DPLL_FINT_INVALID;
+
+ } else if (fint > DPLL_FINT_BAND2_MAX) {
+
+ pr_debug("rejecting n=%d due to Fint failure, "
+ "boosting min_divider\n", n);
+ dd->min_divider = n;
+ ret = DPLL_FINT_INVALID;
+
+ }
+
+ return ret;
+}
/**
* omap2_init_clk_clkdm - look up a clockdomain name, store pointer in clk
clk->name, clks->parent->name,
((clk->parent) ?
clk->parent->name : "NULL"));
+ if (clk->parent)
+ omap_clk_del_child(clk->parent,
+ clk);
clk->parent = clks->parent;
+ omap_clk_add_child(clk->parent, clk);
};
found = 1;
}
/**
* omap2_get_dpll_rate - returns the current DPLL CLKOUT rate
* @clk: struct clk * of a DPLL
+ * @parent_rate: rate of the parent of the DPLL clock
*
* DPLLs can be locked or bypassed - basically, enabled or disabled.
* When locked, the DPLL output depends on the M and N values. When
* locked, or the appropriate bypass rate if the DPLL is bypassed, or 0
* if the clock @clk is not a DPLL.
*/
-u32 omap2_get_dpll_rate(struct clk *clk)
+u32 omap2_get_dpll_rate(struct clk *clk, unsigned long parent_rate)
{
long long dpll_clk;
u32 dpll_mult, dpll_div, v;
return 0;
/* Return bypass rate if DPLL is bypassed */
- v = cm_read_mod_reg(clk->prcm_mod, dd->idlest_reg);
- v &= dd->idlest_mask;
- v >>= __ffs(dd->idlest_mask);
+ v = cm_read_mod_reg(clk->prcm_mod, dd->control_reg);
+ v &= dd->enable_mask;
+ v >>= __ffs(dd->enable_mask);
+
if (cpu_is_omap24xx()) {
- if (v == ST_CORE_CLK_REF)
- return clk->parent->rate; /* sys_clk */
- else if (v == ST_CORE_CLK_32K)
- return 32768;
+ if (v == OMAP2XXX_EN_DPLL_LPBYPASS ||
+ v == OMAP2XXX_EN_DPLL_FRBYPASS)
+ return parent_rate;
} else if (cpu_is_omap34xx()) {
- if (!v)
+ if (v == OMAP3XXX_EN_DPLL_LPBYPASS ||
+ v == OMAP3XXX_EN_DPLL_FRBYPASS)
return dd->bypass_clk->rate;
}
dpll_div = v & dd->div1_mask;
dpll_div >>= __ffs(dd->div1_mask);
- dpll_clk = (long long)clk->parent->rate * dpll_mult;
+ dpll_clk = (long long)parent_rate * dpll_mult;
do_div(dpll_clk, dpll_div + 1);
return dpll_clk;
* Used for clocks that have the same value as the parent clock,
* divided by some factor
*/
-void omap2_fixed_divisor_recalc(struct clk *clk)
+void omap2_fixed_divisor_recalc(struct clk *clk, unsigned long parent_rate,
+ u8 rate_storage)
{
- WARN_ON(!clk->fixed_div);
+ unsigned long rate;
- clk->rate = clk->parent->rate / clk->fixed_div;
+ WARN_ON(!clk->fixed_div); /* XXX move this to init */
- if (clk->flags & RATE_PROPAGATES)
- propagate_rate(clk);
+ rate = parent_rate / clk->fixed_div;
+
+ if (rate_storage == CURRENT_RATE)
+ clk->rate = rate;
+ else if (rate_storage == TEMP_RATE)
+ clk->temp_rate = rate;
}
/**
* Used for clocks that are part of CLKSEL_xyz governed clocks.
* REVISIT: Maybe change to use clk->enable() functions like on omap1?
*/
-void omap2_clksel_recalc(struct clk *clk)
+void omap2_clksel_recalc(struct clk *clk, unsigned long parent_rate,
+ u8 rate_storage)
{
u32 div = 0;
+ unsigned long rate;
pr_debug("clock: recalc'ing clksel clk %s\n", clk->name);
if (div == 0)
return;
- if (clk->rate == (clk->parent->rate / div))
- return;
- clk->rate = clk->parent->rate / div;
+ rate = parent_rate / div;
- pr_debug("clock: new clock rate is %ld (div %d)\n", clk->rate, div);
+ if (rate_storage == CURRENT_RATE)
+ clk->rate = rate;
+ else if (rate_storage == TEMP_RATE)
+ clk->temp_rate = rate;
- if (clk->flags & RATE_PROPAGATES)
- propagate_rate(clk);
+ pr_debug("clock: new clock rate is %ld (div %d)\n", clk->rate, div);
}
/**
if (clk->round_rate != NULL)
return clk->round_rate(clk, rate);
- if (clk->flags & RATE_FIXED)
- printk(KERN_ERR "clock: generic omap2_clk_round_rate called "
- "on fixed-rate clock %s\n", clk->name);
-
return clk->rate;
}
if (clk->set_rate != NULL)
ret = clk->set_rate(clk, rate);
- if (ret == 0 && (clk->flags & RATE_PROPAGATES))
- propagate_rate(clk);
-
return ret;
}
pr_debug("clock: set parent of %s to %s (new rate %ld)\n",
clk->name, clk->parent->name, clk->rate);
- if (clk->flags & RATE_PROPAGATES)
- propagate_rate(clk);
-
return 0;
}
+struct clk *omap2_clk_get_parent(struct clk *clk)
+{
+ return clk->parent;
+}
+
/* DPLL rate rounding code */
/**
unsigned long target_rate,
unsigned long parent_rate)
{
- int flags = 0, carry = 0;
+ int r = 0, carry = 0;
/* Unscale m and round if necessary */
if (*m % DPLL_SCALE_FACTOR >= DPLL_ROUNDING_VAL)
if (*m < DPLL_MIN_MULTIPLIER) {
*m = DPLL_MIN_MULTIPLIER;
*new_rate = 0;
- flags = DPLL_MULT_UNDERFLOW;
+ r = DPLL_MULT_UNDERFLOW;
}
if (*new_rate == 0)
*new_rate = _dpll_compute_new_rate(parent_rate, *m, n);
- return flags;
+ return r;
}
/**
int m, n, r, e, scaled_max_m;
unsigned long scaled_rt_rp, new_rate;
int min_e = -1, min_e_m = -1, min_e_n = -1;
+ struct dpll_data *dd;
if (!clk || !clk->dpll_data)
return ~0;
+ dd = clk->dpll_data;
+
pr_debug("clock: starting DPLL round_rate for clock %s, target rate "
"%ld\n", clk->name, target_rate);
scaled_rt_rp = target_rate / (clk->parent->rate / DPLL_SCALE_FACTOR);
- scaled_max_m = clk->dpll_data->max_multiplier * DPLL_SCALE_FACTOR;
+ scaled_max_m = dd->max_multiplier * DPLL_SCALE_FACTOR;
- clk->dpll_data->last_rounded_rate = 0;
+ dd->last_rounded_rate = 0;
- for (n = clk->dpll_data->max_divider; n >= DPLL_MIN_DIVIDER; n--) {
+ for (n = dd->min_divider; n <= dd->max_divider; n++) {
+
+ /* Is the (input clk, divider) pair valid for the DPLL? */
+ r = _dpll_test_fint(clk, n);
+ if (r == DPLL_FINT_UNDERFLOW)
+ break;
+ else if (r == DPLL_FINT_INVALID)
+ continue;
/* Compute the scaled DPLL multiplier, based on the divider */
m = scaled_rt_rp * n;
/*
- * Since we're counting n down, a m overflow means we can
- * can immediately skip to the next n
+ * Since we're counting n up, a m overflow means we
+ * can bail out completely (since as n increases in
+ * the next iteration, there's no way that m can
+ * increase beyond the current m)
*/
if (m > scaled_max_m)
- continue;
+ break;
r = _dpll_test_mult(&m, n, &new_rate, target_rate,
clk->parent->rate);
+ /* m can't be set low enough for this n - try with a larger n */
+ if (r == DPLL_MULT_UNDERFLOW)
+ continue;
+
e = target_rate - new_rate;
pr_debug("clock: n = %d: m = %d: rate error is %d "
"(new_rate = %ld)\n", n, m, e, new_rate);
if (min_e == -1 ||
- min_e >= (int)(abs(e) - clk->dpll_data->rate_tolerance)) {
+ min_e >= (int)(abs(e) - dd->rate_tolerance)) {
min_e = e;
min_e_m = m;
min_e_n = n;
pr_debug("clock: found new least error %d\n", min_e);
- }
- /*
- * Since we're counting n down, a m underflow means we
- * can bail out completely (since as n decreases in
- * the next iteration, there's no way that m can
- * increase beyond the current m)
- */
- if (r & DPLL_MULT_UNDERFLOW)
- break;
+ /* We found good settings -- bail out now */
+ if (min_e <= dd->rate_tolerance)
+ break;
+ }
}
if (min_e < 0) {
return ~0;
}
- clk->dpll_data->last_rounded_m = min_e_m;
- clk->dpll_data->last_rounded_n = min_e_n;
- clk->dpll_data->last_rounded_rate =
- _dpll_compute_new_rate(clk->parent->rate, min_e_m, min_e_n);
+ dd->last_rounded_m = min_e_m;
+ dd->last_rounded_n = min_e_n;
+ dd->last_rounded_rate = _dpll_compute_new_rate(clk->parent->rate,
+ min_e_m, min_e_n);
pr_debug("clock: final least error: e = %d, m = %d, n = %d\n",
min_e, min_e_m, min_e_n);
pr_debug("clock: final rate: %ld (target rate: %ld)\n",
- clk->dpll_data->last_rounded_rate, target_rate);
+ dd->last_rounded_rate, target_rate);
- return clk->dpll_data->last_rounded_rate;
+ return dd->last_rounded_rate;
}
/*-------------------------------------------------------------------------
projects / linux-2.6-omap-h63xx.git / blobdiff