diff mbox series

[11/19] clk: at91: clk-generated: pass the id of changeable parent at registration

Message ID 1594812267-6697-12-git-send-email-claudiu.beznea@microchip.com (mailing list archive)
State New, archived
Headers show
Series clk: at91: add sama7g5 clock support | expand

Commit Message

Claudiu Beznea July 15, 2020, 11:24 a.m. UTC 
Pass the ID of changeable parent at registration. This will allow
the scalability of this clock driver with regards to the changeable
parent ID for versions of this IP where changeable parent is not the
last one in the parents list (e.g. SAMA7G5). In
clk_generated_best_diff() the *best_diff variable is check against
tmp_diff variable using ">=" operator instead of ">" so that in case
the requested frequency could be obtained using fix parents + gck
dividers but the clock also supports changeable parent to be able
to force the usage of the changeable parent.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
---
 drivers/clk/at91/clk-generated.c | 26 ++++++++++++++------------
 drivers/clk/at91/dt-compat.c     |  8 +++++---
 drivers/clk/at91/pmc.h           |  4 ++--
 drivers/clk/at91/sam9x60.c       |  3 +--
 drivers/clk/at91/sama5d2.c       | 31 +++++++++++++++----------------
 5 files changed, 37 insertions(+), 35 deletions(-)

Comments

Codrin Ciubotariu July 16, 2020, 4:57 p.m. UTC | #1 
Hi Claudiu,

On 15.07.2020 14:24, Claudiu Beznea wrote:
> Pass the ID of changeable parent at registration. This will allow
> the scalability of this clock driver with regards to the changeable
> parent ID for versions of this IP where changeable parent is not the
> last one in the parents list (e.g. SAMA7G5). In
> clk_generated_best_diff() the *best_diff variable is check against
> tmp_diff variable using ">=" operator instead of ">" so that in case
> the requested frequency could be obtained using fix parents + gck
> dividers but the clock also supports changeable parent to be able
> to force the usage of the changeable parent.

This is a great feature!

> 
> Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
> ---
>   drivers/clk/at91/clk-generated.c | 26 ++++++++++++++------------
>   drivers/clk/at91/dt-compat.c     |  8 +++++---
>   drivers/clk/at91/pmc.h           |  4 ++--
>   drivers/clk/at91/sam9x60.c       |  3 +--
>   drivers/clk/at91/sama5d2.c       | 31 +++++++++++++++----------------
>   5 files changed, 37 insertions(+), 35 deletions(-)
> 
> diff --git a/drivers/clk/at91/clk-generated.c b/drivers/clk/at91/clk-generated.c
> index 2448bdc63425..f9ca04c97128 100644
> --- a/drivers/clk/at91/clk-generated.c
> +++ b/drivers/clk/at91/clk-generated.c
> @@ -18,8 +18,6 @@
>   
>   #define GENERATED_MAX_DIV	255
>   
> -#define GCK_INDEX_DT_AUDIO_PLL	5
> -
>   struct clk_generated {
>   	struct clk_hw hw;
>   	struct regmap *regmap;
> @@ -29,7 +27,7 @@ struct clk_generated {
>   	u32 gckdiv;
>   	const struct clk_pcr_layout *layout;
>   	u8 parent_id;
> -	bool audio_pll_allowed;
> +	int chg_pid;
>   };
>   
>   #define to_clk_generated(hw) \
> @@ -109,7 +107,7 @@ static void clk_generated_best_diff(struct clk_rate_request *req,
>   		tmp_rate = parent_rate / div;
>   	tmp_diff = abs(req->rate - tmp_rate);
>   
> -	if (*best_diff < 0 || *best_diff > tmp_diff) {
> +	if (*best_diff < 0 || *best_diff >= tmp_diff) {
>   		*best_rate = tmp_rate;
>   		*best_diff = tmp_diff;
>   		req->best_parent_rate = parent_rate;
> @@ -129,7 +127,10 @@ static int clk_generated_determine_rate(struct clk_hw *hw,
>   	int i;
>   	u32 div;
>   
> -	for (i = 0; i < clk_hw_get_num_parents(hw) - 1; i++) {
> +	for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
> +		if (gck->chg_pid == i)
> +			continue;
> +

One thing that the previous loop was preventing was to not allow other 
gcks take clk_hw_get_num_parents(hw) - 1 as a parent. So the audio pll 
(last one) was reserved for the gck of the audio peripherals only. With 
this change, any peripheral can use chg_pid as a parent, preventing thus 
its correct use by the peripherals that can actually need and change the 
rate of chg_pid.

>   		parent = clk_hw_get_parent_by_index(hw, i);
>   		if (!parent)
>   			continue;
> @@ -161,10 +162,10 @@ static int clk_generated_determine_rate(struct clk_hw *hw,
>   	 * that the only clks able to modify gck rate are those of audio IPs.
>   	 */

The above comment should be updated.

>   
> -	if (!gck->audio_pll_allowed)
> +	if (gck->chg_pid < 0)
>   		goto end;

Best regards,
Codrin
diff mbox series

Patch

diff --git a/drivers/clk/at91/clk-generated.c b/drivers/clk/at91/clk-generated.c
index 2448bdc63425..f9ca04c97128 100644
--- a/drivers/clk/at91/clk-generated.c
+++ b/drivers/clk/at91/clk-generated.c
@@ -18,8 +18,6 @@ 
 
 #define GENERATED_MAX_DIV	255
 
-#define GCK_INDEX_DT_AUDIO_PLL	5
-
 struct clk_generated {
 	struct clk_hw hw;
 	struct regmap *regmap;
@@ -29,7 +27,7 @@  struct clk_generated {
 	u32 gckdiv;
 	const struct clk_pcr_layout *layout;
 	u8 parent_id;
-	bool audio_pll_allowed;
+	int chg_pid;
 };
 
 #define to_clk_generated(hw) \
@@ -109,7 +107,7 @@  static void clk_generated_best_diff(struct clk_rate_request *req,
 		tmp_rate = parent_rate / div;
 	tmp_diff = abs(req->rate - tmp_rate);
 
-	if (*best_diff < 0 || *best_diff > tmp_diff) {
+	if (*best_diff < 0 || *best_diff >= tmp_diff) {
 		*best_rate = tmp_rate;
 		*best_diff = tmp_diff;
 		req->best_parent_rate = parent_rate;
@@ -129,7 +127,10 @@  static int clk_generated_determine_rate(struct clk_hw *hw,
 	int i;
 	u32 div;
 
-	for (i = 0; i < clk_hw_get_num_parents(hw) - 1; i++) {
+	for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
+		if (gck->chg_pid == i)
+			continue;
+
 		parent = clk_hw_get_parent_by_index(hw, i);
 		if (!parent)
 			continue;
@@ -161,10 +162,10 @@  static int clk_generated_determine_rate(struct clk_hw *hw,
 	 * that the only clks able to modify gck rate are those of audio IPs.
 	 */
 
-	if (!gck->audio_pll_allowed)
+	if (gck->chg_pid < 0)
 		goto end;
 
-	parent = clk_hw_get_parent_by_index(hw, GCK_INDEX_DT_AUDIO_PLL);
+	parent = clk_hw_get_parent_by_index(hw, gck->chg_pid);
 	if (!parent)
 		goto end;
 
@@ -272,8 +273,8 @@  struct clk_hw * __init
 at91_clk_register_generated(struct regmap *regmap, spinlock_t *lock,
 			    const struct clk_pcr_layout *layout,
 			    const char *name, const char **parent_names,
-			    u8 num_parents, u8 id, bool pll_audio,
-			    const struct clk_range *range)
+			    u8 num_parents, u8 id,
+			    const struct clk_range *range, int chg_pid)
 {
 	struct clk_generated *gck;
 	struct clk_init_data init;
@@ -288,15 +289,16 @@  at91_clk_register_generated(struct regmap *regmap, spinlock_t *lock,
 	init.ops = &generated_ops;
 	init.parent_names = parent_names;
 	init.num_parents = num_parents;
-	init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |
-		CLK_SET_RATE_PARENT;
+	init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE;
+	if (chg_pid >= 0)
+		init.flags |= CLK_SET_RATE_PARENT;
 
 	gck->id = id;
 	gck->hw.init = &init;
 	gck->regmap = regmap;
 	gck->lock = lock;
 	gck->range = *range;
-	gck->audio_pll_allowed = pll_audio;
+	gck->chg_pid = chg_pid;
 	gck->layout = layout;
 
 	clk_generated_startup(gck);
diff --git a/drivers/clk/at91/dt-compat.c b/drivers/clk/at91/dt-compat.c
index aa1754eac59f..8a652c44c25a 100644
--- a/drivers/clk/at91/dt-compat.c
+++ b/drivers/clk/at91/dt-compat.c
@@ -22,6 +22,8 @@ 
 
 #define SYSTEM_MAX_ID		31
 
+#define GCK_INDEX_DT_AUDIO_PLL	5
+
 #ifdef CONFIG_HAVE_AT91_AUDIO_PLL
 static void __init of_sama5d2_clk_audio_pll_frac_setup(struct device_node *np)
 {
@@ -135,7 +137,7 @@  static void __init of_sama5d2_clk_generated_setup(struct device_node *np)
 		return;
 
 	for_each_child_of_node(np, gcknp) {
-		bool pll_audio = false;
+		int chg_pid = INT_MIN;
 
 		if (of_property_read_u32(gcknp, "reg", &id))
 			continue;
@@ -152,12 +154,12 @@  static void __init of_sama5d2_clk_generated_setup(struct device_node *np)
 		if (of_device_is_compatible(np, "atmel,sama5d2-clk-generated") &&
 		    (id == GCK_ID_I2S0 || id == GCK_ID_I2S1 ||
 		     id == GCK_ID_CLASSD))
-			pll_audio = true;
+			chg_pid = GCK_INDEX_DT_AUDIO_PLL;
 
 		hw = at91_clk_register_generated(regmap, &pmc_pcr_lock,
 						 &dt_pcr_layout, name,
 						 parent_names, num_parents,
-						 id, pll_audio, &range);
+						 id, &range, chg_pid);
 		if (IS_ERR(hw))
 			continue;
 
diff --git a/drivers/clk/at91/pmc.h b/drivers/clk/at91/pmc.h
index df616f2937e7..949b1a7b91e5 100644
--- a/drivers/clk/at91/pmc.h
+++ b/drivers/clk/at91/pmc.h
@@ -122,8 +122,8 @@  struct clk_hw * __init
 at91_clk_register_generated(struct regmap *regmap, spinlock_t *lock,
 			    const struct clk_pcr_layout *layout,
 			    const char *name, const char **parent_names,
-			    u8 num_parents, u8 id, bool pll_audio,
-			    const struct clk_range *range);
+			    u8 num_parents, u8 id,
+			    const struct clk_range *range, int chg_pid);
 
 struct clk_hw * __init
 at91_clk_register_h32mx(struct regmap *regmap, const char *name,
diff --git a/drivers/clk/at91/sam9x60.c b/drivers/clk/at91/sam9x60.c
index c8703d2a0886..c4e34c0909e3 100644
--- a/drivers/clk/at91/sam9x60.c
+++ b/drivers/clk/at91/sam9x60.c
@@ -290,8 +290,7 @@  static void __init sam9x60_pmc_setup(struct device_node *np)
 						 sam9x60_gck[i].n,
 						 parent_names, 6,
 						 sam9x60_gck[i].id,
-						 false,
-						 &sam9x60_gck[i].r);
+						 &sam9x60_gck[i].r, INT_MIN);
 		if (IS_ERR(hw))
 			goto err_free;
 
diff --git a/drivers/clk/at91/sama5d2.c b/drivers/clk/at91/sama5d2.c
index d69421d71daf..42637d9531d3 100644
--- a/drivers/clk/at91/sama5d2.c
+++ b/drivers/clk/at91/sama5d2.c
@@ -116,21 +116,20 @@  static const struct {
 	char *n;
 	u8 id;
 	struct clk_range r;
-	bool pll;
+	int chg_pid;
 } sama5d2_gck[] = {
-	{ .n = "sdmmc0_gclk", .id = 31, },
-	{ .n = "sdmmc1_gclk", .id = 32, },
-	{ .n = "tcb0_gclk",   .id = 35, .r = { .min = 0, .max = 83000000 }, },
-	{ .n = "tcb1_gclk",   .id = 36, .r = { .min = 0, .max = 83000000 }, },
-	{ .n = "pwm_gclk",    .id = 38, .r = { .min = 0, .max = 83000000 }, },
-	{ .n = "isc_gclk",    .id = 46, },
-	{ .n = "pdmic_gclk",  .id = 48, },
-	{ .n = "i2s0_gclk",   .id = 54, .pll = true },
-	{ .n = "i2s1_gclk",   .id = 55, .pll = true },
-	{ .n = "can0_gclk",   .id = 56, .r = { .min = 0, .max = 80000000 }, },
-	{ .n = "can1_gclk",   .id = 57, .r = { .min = 0, .max = 80000000 }, },
-	{ .n = "classd_gclk", .id = 59, .r = { .min = 0, .max = 100000000 },
-	  .pll = true },
+	{ .n = "sdmmc0_gclk", .id = 31, .chg_pid = INT_MIN, },
+	{ .n = "sdmmc1_gclk", .id = 32, .chg_pid = INT_MIN, },
+	{ .n = "tcb0_gclk",   .id = 35, .chg_pid = INT_MIN, .r = { .min = 0, .max = 83000000 }, },
+	{ .n = "tcb1_gclk",   .id = 36, .chg_pid = INT_MIN, .r = { .min = 0, .max = 83000000 }, },
+	{ .n = "pwm_gclk",    .id = 38, .chg_pid = INT_MIN, .r = { .min = 0, .max = 83000000 }, },
+	{ .n = "isc_gclk",    .id = 46, .chg_pid = INT_MIN, },
+	{ .n = "pdmic_gclk",  .id = 48, .chg_pid = INT_MIN, },
+	{ .n = "i2s0_gclk",   .id = 54, .chg_pid = 5, },
+	{ .n = "i2s1_gclk",   .id = 55, .chg_pid = 5, },
+	{ .n = "can0_gclk",   .id = 56, .chg_pid = INT_MIN, .r = { .min = 0, .max = 80000000 }, },
+	{ .n = "can1_gclk",   .id = 57, .chg_pid = INT_MIN, .r = { .min = 0, .max = 80000000 }, },
+	{ .n = "classd_gclk", .id = 59, .chg_pid = 5, .r = { .min = 0, .max = 100000000 }, },
 };
 
 static const struct clk_programmable_layout sama5d2_programmable_layout = {
@@ -324,8 +323,8 @@  static void __init sama5d2_pmc_setup(struct device_node *np)
 						 sama5d2_gck[i].n,
 						 parent_names, 6,
 						 sama5d2_gck[i].id,
-						 sama5d2_gck[i].pll,
-						 &sama5d2_gck[i].r);
+						 &sama5d2_gck[i].r,
+						 sama5d2_gck[i].chg_pid);
 		if (IS_ERR(hw))
 			goto err_free;