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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-03-25 03:53:42 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-03-25 03:53:42 -0300
commit03dd4cb26d967f9588437b0fc9cc0e8353322bb7 (patch)
treefa581f6dc1c0596391690d1f67eceef3af8246dc /drivers/clk/bcm/clk-bcm2835.c
parentd4e493caf788ef44982e131ff9c786546904d934 (diff)
Linux-libre 4.5-gnu
Diffstat (limited to 'drivers/clk/bcm/clk-bcm2835.c')
-rw-r--r--drivers/clk/bcm/clk-bcm2835.c155
1 files changed, 101 insertions, 54 deletions
diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c
index 39bf58202..015e687ff 100644
--- a/drivers/clk/bcm/clk-bcm2835.c
+++ b/drivers/clk/bcm/clk-bcm2835.c
@@ -807,6 +807,16 @@ static const struct bcm2835_clock_data bcm2835_clock_emmc_data = {
.frac_bits = 8,
};
+static const struct bcm2835_clock_data bcm2835_clock_pwm_data = {
+ .name = "pwm",
+ .num_mux_parents = ARRAY_SIZE(bcm2835_clock_per_parents),
+ .parents = bcm2835_clock_per_parents,
+ .ctl_reg = CM_PWMCTL,
+ .div_reg = CM_PWMDIV,
+ .int_bits = 12,
+ .frac_bits = 12,
+};
+
struct bcm2835_pll {
struct clk_hw hw;
struct bcm2835_cprman *cprman;
@@ -1148,22 +1158,24 @@ static int bcm2835_clock_is_on(struct clk_hw *hw)
static u32 bcm2835_clock_choose_div(struct clk_hw *hw,
unsigned long rate,
- unsigned long parent_rate)
+ unsigned long parent_rate,
+ bool round_up)
{
struct bcm2835_clock *clock = bcm2835_clock_from_hw(hw);
const struct bcm2835_clock_data *data = clock->data;
- u32 unused_frac_mask = GENMASK(CM_DIV_FRAC_BITS - data->frac_bits, 0);
+ u32 unused_frac_mask =
+ GENMASK(CM_DIV_FRAC_BITS - data->frac_bits, 0) >> 1;
u64 temp = (u64)parent_rate << CM_DIV_FRAC_BITS;
+ u64 rem;
u32 div;
- do_div(temp, rate);
+ rem = do_div(temp, rate);
div = temp;
- /* Round and mask off the unused bits */
- if (unused_frac_mask != 0) {
- div += unused_frac_mask >> 1;
- div &= ~unused_frac_mask;
- }
+ /* Round up and mask off the unused bits */
+ if (round_up && ((div & unused_frac_mask) != 0 || rem != 0))
+ div += unused_frac_mask + 1;
+ div &= ~unused_frac_mask;
/* Clamp to the limits. */
div = max(div, unused_frac_mask + 1);
@@ -1197,16 +1209,6 @@ static long bcm2835_clock_rate_from_divisor(struct bcm2835_clock *clock,
return temp;
}
-static long bcm2835_clock_round_rate(struct clk_hw *hw,
- unsigned long rate,
- unsigned long *parent_rate)
-{
- struct bcm2835_clock *clock = bcm2835_clock_from_hw(hw);
- u32 div = bcm2835_clock_choose_div(hw, rate, *parent_rate);
-
- return bcm2835_clock_rate_from_divisor(clock, *parent_rate, div);
-}
-
static unsigned long bcm2835_clock_get_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
@@ -1271,20 +1273,82 @@ static int bcm2835_clock_set_rate(struct clk_hw *hw,
struct bcm2835_clock *clock = bcm2835_clock_from_hw(hw);
struct bcm2835_cprman *cprman = clock->cprman;
const struct bcm2835_clock_data *data = clock->data;
- u32 div = bcm2835_clock_choose_div(hw, rate, parent_rate);
+ u32 div = bcm2835_clock_choose_div(hw, rate, parent_rate, false);
cprman_write(cprman, data->div_reg, div);
return 0;
}
+static int bcm2835_clock_determine_rate(struct clk_hw *hw,
+ struct clk_rate_request *req)
+{
+ struct bcm2835_clock *clock = bcm2835_clock_from_hw(hw);
+ struct clk_hw *parent, *best_parent = NULL;
+ unsigned long rate, best_rate = 0;
+ unsigned long prate, best_prate = 0;
+ size_t i;
+ u32 div;
+
+ /*
+ * Select parent clock that results in the closest but lower rate
+ */
+ for (i = 0; i < clk_hw_get_num_parents(hw); ++i) {
+ parent = clk_hw_get_parent_by_index(hw, i);
+ if (!parent)
+ continue;
+ prate = clk_hw_get_rate(parent);
+ div = bcm2835_clock_choose_div(hw, req->rate, prate, true);
+ rate = bcm2835_clock_rate_from_divisor(clock, prate, div);
+ if (rate > best_rate && rate <= req->rate) {
+ best_parent = parent;
+ best_prate = prate;
+ best_rate = rate;
+ }
+ }
+
+ if (!best_parent)
+ return -EINVAL;
+
+ req->best_parent_hw = best_parent;
+ req->best_parent_rate = best_prate;
+
+ req->rate = best_rate;
+
+ return 0;
+}
+
+static int bcm2835_clock_set_parent(struct clk_hw *hw, u8 index)
+{
+ struct bcm2835_clock *clock = bcm2835_clock_from_hw(hw);
+ struct bcm2835_cprman *cprman = clock->cprman;
+ const struct bcm2835_clock_data *data = clock->data;
+ u8 src = (index << CM_SRC_SHIFT) & CM_SRC_MASK;
+
+ cprman_write(cprman, data->ctl_reg, src);
+ return 0;
+}
+
+static u8 bcm2835_clock_get_parent(struct clk_hw *hw)
+{
+ struct bcm2835_clock *clock = bcm2835_clock_from_hw(hw);
+ struct bcm2835_cprman *cprman = clock->cprman;
+ const struct bcm2835_clock_data *data = clock->data;
+ u32 src = cprman_read(cprman, data->ctl_reg);
+
+ return (src & CM_SRC_MASK) >> CM_SRC_SHIFT;
+}
+
+
static const struct clk_ops bcm2835_clock_clk_ops = {
.is_prepared = bcm2835_clock_is_on,
.prepare = bcm2835_clock_on,
.unprepare = bcm2835_clock_off,
.recalc_rate = bcm2835_clock_get_rate,
.set_rate = bcm2835_clock_set_rate,
- .round_rate = bcm2835_clock_round_rate,
+ .determine_rate = bcm2835_clock_determine_rate,
+ .set_parent = bcm2835_clock_set_parent,
+ .get_parent = bcm2835_clock_get_parent,
};
static int bcm2835_vpu_clock_is_on(struct clk_hw *hw)
@@ -1300,7 +1364,9 @@ static const struct clk_ops bcm2835_vpu_clock_clk_ops = {
.is_prepared = bcm2835_vpu_clock_is_on,
.recalc_rate = bcm2835_clock_get_rate,
.set_rate = bcm2835_clock_set_rate,
- .round_rate = bcm2835_clock_round_rate,
+ .determine_rate = bcm2835_clock_determine_rate,
+ .set_parent = bcm2835_clock_set_parent,
+ .get_parent = bcm2835_clock_get_parent,
};
static struct clk *bcm2835_register_pll(struct bcm2835_cprman *cprman,
@@ -1394,45 +1460,23 @@ static struct clk *bcm2835_register_clock(struct bcm2835_cprman *cprman,
{
struct bcm2835_clock *clock;
struct clk_init_data init;
- const char *parent;
+ const char *parents[1 << CM_SRC_BITS];
+ size_t i;
/*
- * Most of the clock generators have a mux field, so we
- * instantiate a generic mux as our parent to handle it.
+ * Replace our "xosc" references with the oscillator's
+ * actual name.
*/
- if (data->num_mux_parents) {
- const char *parents[1 << CM_SRC_BITS];
- int i;
-
- parent = devm_kasprintf(cprman->dev, GFP_KERNEL,
- "mux_%s", data->name);
- if (!parent)
- return NULL;
-
- /*
- * Replace our "xosc" references with the oscillator's
- * actual name.
- */
- for (i = 0; i < data->num_mux_parents; i++) {
- if (strcmp(data->parents[i], "xosc") == 0)
- parents[i] = cprman->osc_name;
- else
- parents[i] = data->parents[i];
- }
-
- clk_register_mux(cprman->dev, parent,
- parents, data->num_mux_parents,
- CLK_SET_RATE_PARENT,
- cprman->regs + data->ctl_reg,
- CM_SRC_SHIFT, CM_SRC_BITS,
- 0, &cprman->regs_lock);
- } else {
- parent = data->parents[0];
+ for (i = 0; i < data->num_mux_parents; i++) {
+ if (strcmp(data->parents[i], "xosc") == 0)
+ parents[i] = cprman->osc_name;
+ else
+ parents[i] = data->parents[i];
}
memset(&init, 0, sizeof(init));
- init.parent_names = &parent;
- init.num_parents = 1;
+ init.parent_names = parents;
+ init.num_parents = data->num_mux_parents;
init.name = data->name;
init.flags = CLK_IGNORE_UNUSED;
@@ -1550,6 +1594,9 @@ static int bcm2835_clk_probe(struct platform_device *pdev)
cprman->regs + CM_PERIICTL, CM_GATE_BIT,
0, &cprman->regs_lock);
+ clks[BCM2835_CLOCK_PWM] =
+ bcm2835_register_clock(cprman, &bcm2835_clock_pwm_data);
+
return of_clk_add_provider(dev->of_node, of_clk_src_onecell_get,
&cprman->onecell);
}