summaryrefslogtreecommitdiff
path: root/drivers/clk/at91/clk-generated.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2017-09-13 11:04:14 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-09-13 11:04:14 -0700
commitf60a2abfdbf298a4722dfef331c38447fa18c4e3 (patch)
tree1ac56db32fb1909aedefc21b1c62d0bbe5a13e68 /drivers/clk/at91/clk-generated.c
parent561a8eb3e1d219f415597c76dae44b530b7f961a (diff)
parent73c950da6ec523136090d6d4d6907a6ea8e8b67b (diff)
Merge tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux
Pull clk updates from Stephen Boyd: "The diff is dominated by the Allwinner A10/A20 SoCs getting converted to the sunxi-ng framework. Otherwise, the heavy hitters are various drivers for SoCs like AT91, Amlogic, Renesas, and Rockchip. There are some other new clk drivers in here too but overall this is just a bunch of clk drivers for various different pieces of hardware and a collection of non-critical fixes for clk drivers. New Drivers: - Allwinner R40 SoCs - Renesas R-Car Gen3 USB 2.0 clock selector PHY - Atmel AT91 audio PLL - Uniphier PXs3 SoCs - ARC HSDK Board PLLs - AXS10X Board PLLs - STMicroelectronics STM32H743 SoCs Removed Drivers: - Non-compiling mb86s7x support Updates: - Allwinner A10/A20 SoCs converted to sunxi-ng framework - Allwinner H3 CPU clk fixes - Renesas R-Car D3 SoC - Renesas V2H and M3-W modules - Samsung Exynos5420/5422/5800 audio fixes - Rockchip fractional clk approximation fixes - Rockchip rk3126 SoC support within the rk3128 driver - Amlogic gxbb CEC32 and sd_emmc clks - Amlogic meson8b reset controller support - IDT VersaClock 5P49V5925/5P49V6901 support - Qualcomm MSM8996 SMMU clks - Various 'const' applications for struct clk_ops - si5351 PLL reset bugfix - Uniphier audio on LD11/LD20 and ethernet support on LD11/LD20/Pro4/PXs2 - Assorted Tegra clk driver fixes" * tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux: (120 commits) clk: si5351: fix PLL reset ASoC: atmel-classd: remove aclk clock ASoC: atmel-classd: remove aclk clock from DT binding clk: at91: clk-generated: make gclk determine audio_pll rate clk: at91: clk-generated: create function to find best_diff clk: at91: add audio pll clock drivers dt-bindings: clk: at91: add audio plls to the compatible list clk: at91: clk-generated: remove useless divisor loop clk: mb86s7x: Drop non-building driver clk: ti: check for null return in strrchr to avoid null dereferencing clk: Don't write error code into divider register clk: uniphier: add video input subsystem clock clk: uniphier: add audio system clock clk: stm32h7: Add stm32h743 clock driver clk: gate: expose clk_gate_ops::is_enabled clk: nxp: clk-lpc32xx: rename clk_gate_is_enabled() clk: uniphier: add PXs3 clock data clk: hi6220: change watchdog clock source clk: Kconfig: Name RK805 in Kconfig for COMMON_CLK_RK808 clk: cs2000: Add cs2000_set_saved_rate ...
Diffstat (limited to 'drivers/clk/at91/clk-generated.c')
-rw-r--r--drivers/clk/at91/clk-generated.c101
1 files changed, 82 insertions, 19 deletions
diff --git a/drivers/clk/at91/clk-generated.c b/drivers/clk/at91/clk-generated.c
index f0b7ae904ce2..33481368740e 100644
--- a/drivers/clk/at91/clk-generated.c
+++ b/drivers/clk/at91/clk-generated.c
@@ -26,6 +26,13 @@
#define GENERATED_SOURCE_MAX 6
#define GENERATED_MAX_DIV 255
+#define GCK_ID_SSC0 43
+#define GCK_ID_SSC1 44
+#define GCK_ID_I2S0 54
+#define GCK_ID_I2S1 55
+#define GCK_ID_CLASSD 59
+#define GCK_INDEX_DT_AUDIO_PLL 5
+
struct clk_generated {
struct clk_hw hw;
struct regmap *regmap;
@@ -34,6 +41,7 @@ struct clk_generated {
u32 id;
u32 gckdiv;
u8 parent_id;
+ bool audio_pll_allowed;
};
#define to_clk_generated(hw) \
@@ -99,21 +107,41 @@ clk_generated_recalc_rate(struct clk_hw *hw,
return DIV_ROUND_CLOSEST(parent_rate, gck->gckdiv + 1);
}
+static void clk_generated_best_diff(struct clk_rate_request *req,
+ struct clk_hw *parent,
+ unsigned long parent_rate, u32 div,
+ int *best_diff, long *best_rate)
+{
+ unsigned long tmp_rate;
+ int tmp_diff;
+
+ if (!div)
+ tmp_rate = parent_rate;
+ else
+ tmp_rate = parent_rate / div;
+ 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_generated_determine_rate(struct clk_hw *hw,
struct clk_rate_request *req)
{
struct clk_generated *gck = to_clk_generated(hw);
struct clk_hw *parent = NULL;
+ struct clk_rate_request req_parent = *req;
long best_rate = -EINVAL;
- unsigned long tmp_rate, min_rate;
+ unsigned long min_rate, parent_rate;
int best_diff = -1;
- int tmp_diff;
int i;
+ u32 div;
- for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
- u32 div;
- unsigned long parent_rate;
-
+ for (i = 0; i < clk_hw_get_num_parents(hw) - 1; i++) {
parent = clk_hw_get_parent_by_index(hw, i);
if (!parent)
continue;
@@ -124,25 +152,43 @@ static int clk_generated_determine_rate(struct clk_hw *hw,
(gck->range.max && min_rate > gck->range.max))
continue;
- for (div = 1; div < GENERATED_MAX_DIV + 2; div++) {
- tmp_rate = DIV_ROUND_CLOSEST(parent_rate, div);
- tmp_diff = abs(req->rate - tmp_rate);
+ div = DIV_ROUND_CLOSEST(parent_rate, req->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;
- }
+ clk_generated_best_diff(req, parent, parent_rate, div,
+ &best_diff, &best_rate);
- if (!best_diff || tmp_rate < req->rate)
- break;
- }
+ if (!best_diff)
+ break;
+ }
+
+ /*
+ * The audio_pll rate can be modified, unlike the five others clocks
+ * that should never be altered.
+ * The audio_pll can technically be used by multiple consumers. However,
+ * with the rate locking, the first consumer to enable to clock will be
+ * the one definitely setting the rate of the clock.
+ * Since audio IPs are most likely to request the same rate, we enforce
+ * that the only clks able to modify gck rate are those of audio IPs.
+ */
+
+ if (!gck->audio_pll_allowed)
+ goto end;
+
+ parent = clk_hw_get_parent_by_index(hw, GCK_INDEX_DT_AUDIO_PLL);
+ if (!parent)
+ goto end;
+
+ for (div = 1; div < GENERATED_MAX_DIV + 2; div++) {
+ req_parent.rate = req->rate * div;
+ __clk_determine_rate(parent, &req_parent);
+ clk_generated_best_diff(req, parent, req_parent.rate, div,
+ &best_diff, &best_rate);
if (!best_diff)
break;
}
+end:
pr_debug("GCLK: %s, best_rate = %ld, parent clk: %s @ %ld\n",
__func__, best_rate,
__clk_get_name((req->best_parent_hw)->clk),
@@ -252,7 +298,8 @@ 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;
+ init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |
+ CLK_SET_RATE_PARENT;
gck->id = id;
gck->hw.init = &init;
@@ -284,6 +331,7 @@ static void __init of_sama5d2_clk_generated_setup(struct device_node *np)
struct device_node *gcknp;
struct clk_range range = CLK_RANGE(0, 0);
struct regmap *regmap;
+ struct clk_generated *gck;
num_parents = of_clk_get_parent_count(np);
if (num_parents == 0 || num_parents > GENERATED_SOURCE_MAX)
@@ -315,6 +363,21 @@ static void __init of_sama5d2_clk_generated_setup(struct device_node *np)
hw = at91_clk_register_generated(regmap, &pmc_pcr_lock, name,
parent_names, num_parents,
id, &range);
+
+ gck = to_clk_generated(hw);
+
+ if (of_device_is_compatible(np,
+ "atmel,sama5d2-clk-generated")) {
+ if (gck->id == GCK_ID_SSC0 || gck->id == GCK_ID_SSC1 ||
+ gck->id == GCK_ID_I2S0 || gck->id == GCK_ID_I2S1 ||
+ gck->id == GCK_ID_CLASSD)
+ gck->audio_pll_allowed = true;
+ else
+ gck->audio_pll_allowed = false;
+ } else {
+ gck->audio_pll_allowed = false;
+ }
+
if (IS_ERR(hw))
continue;