aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/clk/bcm/clk-iproc-pll.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/clk/bcm/clk-iproc-pll.c')
-rw-r--r--drivers/clk/bcm/clk-iproc-pll.c97
1 files changed, 82 insertions, 15 deletions
diff --git a/drivers/clk/bcm/clk-iproc-pll.c b/drivers/clk/bcm/clk-iproc-pll.c
index 375d8dd80d45..9514ecf319b0 100644
--- a/drivers/clk/bcm/clk-iproc-pll.c
+++ b/drivers/clk/bcm/clk-iproc-pll.c
@@ -95,6 +95,39 @@ struct iproc_pll {
#define to_iproc_clk(hw) container_of(hw, struct iproc_clk, hw)
+static int pll_calc_param(unsigned long target_rate,
+ unsigned long parent_rate,
+ struct iproc_pll_vco_param *vco_out)
+{
+ u64 ndiv_int, ndiv_frac, residual;
+
+ ndiv_int = target_rate / parent_rate;
+
+ if (!ndiv_int || (ndiv_int > 255))
+ return -EINVAL;
+
+ residual = target_rate - (ndiv_int * parent_rate);
+ residual <<= 20;
+
+ /*
+ * Add half of the divisor so the result will be rounded to closest
+ * instead of rounded down.
+ */
+ residual += (parent_rate / 2);
+ ndiv_frac = div64_u64((u64)residual, (u64)parent_rate);
+
+ vco_out->ndiv_int = ndiv_int;
+ vco_out->ndiv_frac = ndiv_frac;
+ vco_out->pdiv = 1;
+
+ vco_out->rate = vco_out->ndiv_int * parent_rate;
+ residual = (u64)vco_out->ndiv_frac * (u64)parent_rate;
+ residual >>= 20;
+ vco_out->rate += residual;
+
+ return 0;
+}
+
/*
* Based on the target frequency, find a match from the VCO frequency parameter
* table and return its index
@@ -252,11 +285,10 @@ static void __pll_bring_out_reset(struct iproc_pll *pll, unsigned int kp,
iproc_pll_write(pll, pll->control_base, reset->offset, val);
}
-static int pll_set_rate(struct iproc_clk *clk, unsigned int rate_index,
+static int pll_set_rate(struct iproc_clk *clk, struct iproc_pll_vco_param *vco,
unsigned long parent_rate)
{
struct iproc_pll *pll = clk->pll;
- const struct iproc_pll_vco_param *vco = &pll->vco_param[rate_index];
const struct iproc_pll_ctrl *ctrl = pll->ctrl;
int ka = 0, ki, kp, ret;
unsigned long rate = vco->rate;
@@ -431,25 +463,50 @@ static unsigned long iproc_pll_recalc_rate(struct clk_hw *hw,
return clk->rate;
}
-static long iproc_pll_round_rate(struct clk_hw *hw, unsigned long rate,
- unsigned long *parent_rate)
+static int iproc_pll_determine_rate(struct clk_hw *hw,
+ struct clk_rate_request *req)
{
- unsigned i;
+ unsigned int i;
struct iproc_clk *clk = to_iproc_clk(hw);
struct iproc_pll *pll = clk->pll;
+ const struct iproc_pll_ctrl *ctrl = pll->ctrl;
+ unsigned long diff, best_diff;
+ unsigned int best_idx = 0;
+ int ret;
- if (rate == 0 || *parent_rate == 0 || !pll->vco_param)
+ if (req->rate == 0 || req->best_parent_rate == 0)
return -EINVAL;
+ if (ctrl->flags & IPROC_CLK_PLL_CALC_PARAM) {
+ struct iproc_pll_vco_param vco_param;
+
+ ret = pll_calc_param(req->rate, req->best_parent_rate,
+ &vco_param);
+ if (ret)
+ return ret;
+
+ req->rate = vco_param.rate;
+ return 0;
+ }
+
+ if (!pll->vco_param)
+ return -EINVAL;
+
+ best_diff = ULONG_MAX;
for (i = 0; i < pll->num_vco_entries; i++) {
- if (rate <= pll->vco_param[i].rate)
+ diff = abs(req->rate - pll->vco_param[i].rate);
+ if (diff <= best_diff) {
+ best_diff = diff;
+ best_idx = i;
+ }
+ /* break now if perfect match */
+ if (diff == 0)
break;
}
- if (i == pll->num_vco_entries)
- i--;
+ req->rate = pll->vco_param[best_idx].rate;
- return pll->vco_param[i].rate;
+ return 0;
}
static int iproc_pll_set_rate(struct clk_hw *hw, unsigned long rate,
@@ -457,13 +514,23 @@ static int iproc_pll_set_rate(struct clk_hw *hw, unsigned long rate,
{
struct iproc_clk *clk = to_iproc_clk(hw);
struct iproc_pll *pll = clk->pll;
+ const struct iproc_pll_ctrl *ctrl = pll->ctrl;
+ struct iproc_pll_vco_param vco_param;
int rate_index, ret;
- rate_index = pll_get_rate_index(pll, rate);
- if (rate_index < 0)
- return rate_index;
+ if (ctrl->flags & IPROC_CLK_PLL_CALC_PARAM) {
+ ret = pll_calc_param(rate, parent_rate, &vco_param);
+ if (ret)
+ return ret;
+ } else {
+ rate_index = pll_get_rate_index(pll, rate);
+ if (rate_index < 0)
+ return rate_index;
+
+ vco_param = pll->vco_param[rate_index];
+ }
- ret = pll_set_rate(clk, rate_index, parent_rate);
+ ret = pll_set_rate(clk, &vco_param, parent_rate);
return ret;
}
@@ -471,7 +538,7 @@ static const struct clk_ops iproc_pll_ops = {
.enable = iproc_pll_enable,
.disable = iproc_pll_disable,
.recalc_rate = iproc_pll_recalc_rate,
- .round_rate = iproc_pll_round_rate,
+ .determine_rate = iproc_pll_determine_rate,
.set_rate = iproc_pll_set_rate,
};

Privacy Policy