clk: at91: clk-peripheral: add support for changeable parent rate

Some peripheral clocks on SAMA7G5 supports requesting parent to change
its rate (image related clocks: csi, csi2dc, isc). Add support
so that if registered with this option the clock rate to be
requested from parent.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/1595403506-8209-14-git-send-email-claudiu.beznea@microchip.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
This commit is contained in:
Claudiu Beznea 2020-07-22 10:38:21 +03:00 committed by Stephen Boyd
parent 75c88143f3
commit b4c115c761
9 changed files with 119 additions and 16 deletions

View File

@ -222,7 +222,7 @@ static void __init at91sam9n12_pmc_setup(struct device_node *np)
at91sam9n12_periphck[i].n,
"masterck",
at91sam9n12_periphck[i].id,
&range);
&range, INT_MIN);
if (IS_ERR(hw))
goto err_free;

View File

@ -257,7 +257,7 @@ static void __init at91sam9x5_pmc_setup(struct device_node *np,
at91sam9x5_periphck[i].n,
"masterck",
at91sam9x5_periphck[i].id,
&range);
&range, INT_MIN);
if (IS_ERR(hw))
goto err_free;
@ -270,7 +270,7 @@ static void __init at91sam9x5_pmc_setup(struct device_node *np,
extra_pcks[i].n,
"masterck",
extra_pcks[i].id,
&range);
&range, INT_MIN);
if (IS_ERR(hw))
goto err_free;

View File

@ -38,6 +38,7 @@ struct clk_sam9x5_peripheral {
u32 div;
const struct clk_pcr_layout *layout;
bool auto_div;
int chg_pid;
};
#define to_clk_sam9x5_peripheral(hw) \
@ -238,6 +239,87 @@ clk_sam9x5_peripheral_recalc_rate(struct clk_hw *hw,
return parent_rate >> periph->div;
}
static void clk_sam9x5_peripheral_best_diff(struct clk_rate_request *req,
struct clk_hw *parent,
unsigned long parent_rate,
u32 shift, long *best_diff,
long *best_rate)
{
unsigned long tmp_rate = parent_rate >> shift;
unsigned long tmp_diff = abs(req->rate - tmp_rate);
if (*best_diff < 0 || *best_diff >= tmp_diff) {
*best_rate = tmp_rate;
*best_diff = tmp_diff;
req->best_parent_rate = parent_rate;
req->best_parent_hw = parent;
}
}
static int clk_sam9x5_peripheral_determine_rate(struct clk_hw *hw,
struct clk_rate_request *req)
{
struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw);
struct clk_hw *parent = clk_hw_get_parent(hw);
struct clk_rate_request req_parent = *req;
unsigned long parent_rate = clk_hw_get_rate(parent);
unsigned long tmp_rate;
long best_rate = LONG_MIN;
long best_diff = LONG_MIN;
u32 shift;
if (periph->id < PERIPHERAL_ID_MIN || !periph->range.max)
return parent_rate;
/* Fist step: check the available dividers. */
for (shift = 0; shift <= PERIPHERAL_MAX_SHIFT; shift++) {
tmp_rate = parent_rate >> shift;
if (periph->range.max && tmp_rate > periph->range.max)
continue;
clk_sam9x5_peripheral_best_diff(req, parent, parent_rate,
shift, &best_diff, &best_rate);
if (!best_diff || best_rate <= req->rate)
break;
}
if (periph->chg_pid < 0)
goto end;
/* Step two: try to request rate from parent. */
parent = clk_hw_get_parent_by_index(hw, periph->chg_pid);
if (!parent)
goto end;
for (shift = 0; shift <= PERIPHERAL_MAX_SHIFT; shift++) {
req_parent.rate = req->rate << shift;
if (__clk_determine_rate(parent, &req_parent))
continue;
clk_sam9x5_peripheral_best_diff(req, parent, req_parent.rate,
shift, &best_diff, &best_rate);
if (!best_diff)
break;
}
end:
if (best_rate < 0 ||
(periph->range.max && best_rate > periph->range.max))
return -EINVAL;
pr_debug("PCK: %s, best_rate = %ld, parent clk: %s @ %ld\n",
__func__, best_rate,
__clk_get_name((req->best_parent_hw)->clk),
req->best_parent_rate);
req->rate = best_rate;
return 0;
}
static long clk_sam9x5_peripheral_round_rate(struct clk_hw *hw,
unsigned long rate,
unsigned long *parent_rate)
@ -320,11 +402,21 @@ static const struct clk_ops sam9x5_peripheral_ops = {
.set_rate = clk_sam9x5_peripheral_set_rate,
};
static const struct clk_ops sam9x5_peripheral_chg_ops = {
.enable = clk_sam9x5_peripheral_enable,
.disable = clk_sam9x5_peripheral_disable,
.is_enabled = clk_sam9x5_peripheral_is_enabled,
.recalc_rate = clk_sam9x5_peripheral_recalc_rate,
.determine_rate = clk_sam9x5_peripheral_determine_rate,
.set_rate = clk_sam9x5_peripheral_set_rate,
};
struct clk_hw * __init
at91_clk_register_sam9x5_peripheral(struct regmap *regmap, spinlock_t *lock,
const struct clk_pcr_layout *layout,
const char *name, const char *parent_name,
u32 id, const struct clk_range *range)
u32 id, const struct clk_range *range,
int chg_pid)
{
struct clk_sam9x5_peripheral *periph;
struct clk_init_data init;
@ -339,10 +431,16 @@ at91_clk_register_sam9x5_peripheral(struct regmap *regmap, spinlock_t *lock,
return ERR_PTR(-ENOMEM);
init.name = name;
init.ops = &sam9x5_peripheral_ops;
init.parent_names = (parent_name ? &parent_name : NULL);
init.num_parents = (parent_name ? 1 : 0);
init.flags = 0;
init.parent_names = &parent_name;
init.num_parents = 1;
if (chg_pid < 0) {
init.flags = 0;
init.ops = &sam9x5_peripheral_ops;
} else {
init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |
CLK_SET_RATE_PARENT;
init.ops = &sam9x5_peripheral_chg_ops;
}
periph->id = id;
periph->hw.init = &init;
@ -353,6 +451,7 @@ at91_clk_register_sam9x5_peripheral(struct regmap *regmap, spinlock_t *lock,
periph->auto_div = true;
periph->layout = layout;
periph->range = *range;
periph->chg_pid = chg_pid;
hw = &periph->hw;
ret = clk_hw_register(NULL, &periph->hw);

View File

@ -463,7 +463,8 @@ of_at91_clk_periph_setup(struct device_node *np, u8 type)
&dt_pcr_layout,
name,
parent_name,
id, &range);
id, &range,
INT_MIN);
}
if (IS_ERR(hw))

View File

@ -168,7 +168,8 @@ struct clk_hw * __init
at91_clk_register_sam9x5_peripheral(struct regmap *regmap, spinlock_t *lock,
const struct clk_pcr_layout *layout,
const char *name, const char *parent_name,
u32 id, const struct clk_range *range);
u32 id, const struct clk_range *range,
int chg_pid);
struct clk_hw * __init
at91_clk_register_pll(struct regmap *regmap, const char *name,

View File

@ -277,7 +277,7 @@ static void __init sam9x60_pmc_setup(struct device_node *np)
sam9x60_periphck[i].n,
"masterck",
sam9x60_periphck[i].id,
&range);
&range, INT_MIN);
if (IS_ERR(hw))
goto err_free;

View File

@ -291,7 +291,7 @@ static void __init sama5d2_pmc_setup(struct device_node *np)
sama5d2_periphck[i].n,
"masterck",
sama5d2_periphck[i].id,
&range);
&range, INT_MIN);
if (IS_ERR(hw))
goto err_free;
@ -304,7 +304,8 @@ static void __init sama5d2_pmc_setup(struct device_node *np)
sama5d2_periph32ck[i].n,
"h32mxck",
sama5d2_periph32ck[i].id,
&sama5d2_periph32ck[i].r);
&sama5d2_periph32ck[i].r,
INT_MIN);
if (IS_ERR(hw))
goto err_free;

View File

@ -223,7 +223,8 @@ static void __init sama5d3_pmc_setup(struct device_node *np)
sama5d3_periphck[i].n,
"masterck",
sama5d3_periphck[i].id,
&sama5d3_periphck[i].r);
&sama5d3_periphck[i].r,
INT_MIN);
if (IS_ERR(hw))
goto err_free;

View File

@ -246,7 +246,7 @@ static void __init sama5d4_pmc_setup(struct device_node *np)
sama5d4_periphck[i].n,
"masterck",
sama5d4_periphck[i].id,
&range);
&range, INT_MIN);
if (IS_ERR(hw))
goto err_free;
@ -259,7 +259,7 @@ static void __init sama5d4_pmc_setup(struct device_node *np)
sama5d4_periph32ck[i].n,
"h32mxck",
sama5d4_periph32ck[i].id,
&range);
&range, INT_MIN);
if (IS_ERR(hw))
goto err_free;