Thread (2 messages) flat view 2 messages, 2 authors, 2014-02-28
STALE4582d

[PATCH 05/12] CLK: TI: APLL: add support for omap2 aplls

From: Tero Kristo <hidden>
Date: 2014-02-28 09:22:57
Also in: linux-devicetree, linux-omap
Subsystem: arm port, common clk framework, omap clock framework support, omap2+ support, open firmware and flattened device tree bindings, the rest, ti clock driver · Maintainers: Russell King, Stephen Boyd, Brian Masney, Jerome Brunet, Paul Walmsley, Aaro Koskinen, Andreas Kemnade, Kevin Hilman, Roger Quadros, Tony Lindgren, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Linus Torvalds, Tero Kristo

This patch adds support for omap2 type aplls, which have gating and
autoidle functionality.

Signed-off-by: Tero Kristo <redacted>
---
 .../devicetree/bindings/clock/ti/apll.txt          |   21 ++-
 arch/arm/mach-omap2/clock.h                        |   11 --
 drivers/clk/ti/apll.c                              |  180 ++++++++++++++++++++
 include/linux/clk/ti.h                             |   21 ++-
 4 files changed, 216 insertions(+), 17 deletions(-)
diff --git a/Documentation/devicetree/bindings/clock/ti/apll.txt b/Documentation/devicetree/bindings/clock/ti/apll.txt
index 7faf5a6..61ecd30 100644
--- a/Documentation/devicetree/bindings/clock/ti/apll.txt
+++ b/Documentation/devicetree/bindings/clock/ti/apll.txt
@@ -14,18 +14,29 @@ a subtype of a DPLL [2], although a simplified one at that.
 [2] Documentation/devicetree/bindings/clock/ti/dpll.txt
 
 Required properties:
-- compatible : shall be "ti,dra7-apll-clock"
+- compatible : shall be "ti,dra7-apll-clock" or "ti,omap2-apll-clock"
 - #clock-cells : from common clock binding; shall be set to 0.
 - clocks : link phandles of parent clocks (clk-ref and clk-bypass)
 - reg : address and length of the register set for controlling the APLL.
   It contains the information of registers in the following order:
-	"control" - contains the control register base address
-	"idlest" - contains the idlest register base address
+	"control" - contains the control register offset
+	"idlest" - contains the idlest register offset
+	"autoidle" - contains the autoidle register offset (OMAP2 only)
 
 Examples:
-	apll_pcie_ck: apll_pcie_ck at 4a008200 {
+	apll_pcie_ck: apll_pcie_ck {
 		#clock-cells = <0>;
 		clocks = <&apll_pcie_in_clk_mux>, <&dpll_pcie_ref_ck>;
-		reg = <0x4a00821c 0x4>, <0x4a008220 0x4>;
+		reg = <0x021c>, <0x0220>;
 		compatible = "ti,dra7-apll-clock";
 	};
+
+	apll96_ck: apll96_ck {
+		#clock-cells = <0>;
+		compatible = "ti,omap2-apll-clock";
+		clocks = <&sys_ck>;
+		ti,bit-shift = <2>;
+		ti,idlest-shift = <8>;
+		ti,clock-frequency = <96000000>;
+		reg = <0x0500>, <0x0530>, <0x0520>;
+	};
diff --git a/arch/arm/mach-omap2/clock.h b/arch/arm/mach-omap2/clock.h
index 7057f37..7b7a03c 100644
--- a/arch/arm/mach-omap2/clock.h
+++ b/arch/arm/mach-omap2/clock.h
@@ -178,17 +178,6 @@ struct clksel {
 	const struct clksel_rate *rates;
 };
 
-struct clk_hw_omap_ops {
-	void			(*find_idlest)(struct clk_hw_omap *oclk,
-					void __iomem **idlest_reg,
-					u8 *idlest_bit, u8 *idlest_val);
-	void			(*find_companion)(struct clk_hw_omap *oclk,
-					void __iomem **other_reg,
-					u8 *other_bit);
-	void			(*allow_idle)(struct clk_hw_omap *oclk);
-	void			(*deny_idle)(struct clk_hw_omap *oclk);
-};
-
 /* CM_CLKSEL2_PLL.CORE_CLK_SRC bits (2XXX) */
 #define CORE_CLK_SRC_32K		0x0
 #define CORE_CLK_SRC_DPLL		0x1
diff --git a/drivers/clk/ti/apll.c b/drivers/clk/ti/apll.c
index b986f61..60b2427 100644
--- a/drivers/clk/ti/apll.c
+++ b/drivers/clk/ti/apll.c
@@ -221,3 +221,183 @@ cleanup:
 	kfree(init);
 }
 CLK_OF_DECLARE(dra7_apll_clock, "ti,dra7-apll-clock", of_dra7_apll_setup);
+
+#define OMAP2_EN_APLL_LOCKED	0x3
+#define OMAP2_EN_APLL_STOPPED	0x0
+
+static int omap2_apll_is_enabled(struct clk_hw *hw)
+{
+	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
+	struct dpll_data *ad = clk->dpll_data;
+	u32 v;
+
+	v = ti_clk_ll_ops->clk_readl(ad->control_reg);
+	v &= ad->enable_mask;
+
+	v >>= __ffs(ad->enable_mask);
+
+	return v == OMAP2_EN_APLL_LOCKED ? 1 : 0;
+}
+
+static unsigned long omap2_apll_recalc(struct clk_hw *hw,
+				       unsigned long parent_rate)
+{
+	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
+
+	if (omap2_apll_is_enabled(hw))
+		return clk->fixed_rate;
+
+	return 0;
+}
+
+static int omap2_apll_enable(struct clk_hw *hw)
+{
+	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
+	struct dpll_data *ad = clk->dpll_data;
+	u32 v;
+	int i = 0;
+
+	v = ti_clk_ll_ops->clk_readl(ad->control_reg);
+	v &= ~ad->enable_mask;
+	v |= OMAP2_EN_APLL_LOCKED << __ffs(ad->enable_mask);
+	ti_clk_ll_ops->clk_writel(v, ad->control_reg);
+
+	while (1) {
+		v = ti_clk_ll_ops->clk_readl(ad->idlest_reg);
+		if (v & ad->idlest_mask)
+			break;
+		if (i > MAX_APLL_WAIT_TRIES)
+			break;
+		i++;
+		udelay(1);
+	}
+
+	if (i == MAX_APLL_WAIT_TRIES) {
+		pr_warn("%s failed to transition to locked\n",
+			__clk_get_name(clk->hw.clk));
+		return -EBUSY;
+	}
+
+	return 0;
+}
+
+static void omap2_apll_disable(struct clk_hw *hw)
+{
+	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
+	struct dpll_data *ad = clk->dpll_data;
+	u32 v;
+
+	v = ti_clk_ll_ops->clk_readl(ad->control_reg);
+	v &= ~ad->enable_mask;
+	v |= OMAP2_EN_APLL_STOPPED << __ffs(ad->enable_mask);
+	ti_clk_ll_ops->clk_writel(v, ad->control_reg);
+}
+
+static struct clk_ops omap2_apll_ops = {
+	.enable		= &omap2_apll_enable,
+	.disable	= &omap2_apll_disable,
+	.is_enabled	= &omap2_apll_is_enabled,
+	.recalc_rate	= &omap2_apll_recalc,
+};
+
+static void omap2_apll_set_autoidle(struct clk_hw_omap *clk, u32 val)
+{
+	struct dpll_data *ad = clk->dpll_data;
+	u32 v;
+
+	v = ti_clk_ll_ops->clk_readl(ad->autoidle_reg);
+	v &= ~ad->autoidle_mask;
+	v |= val << __ffs(ad->autoidle_mask);
+	ti_clk_ll_ops->clk_writel(v, ad->control_reg);
+}
+
+#define OMAP2_APLL_AUTOIDLE_LOW_POWER_STOP	0x3
+#define OMAP2_APLL_AUTOIDLE_DISABLE		0x0
+
+static void omap2_apll_allow_idle(struct clk_hw_omap *clk)
+{
+	omap2_apll_set_autoidle(clk, OMAP2_APLL_AUTOIDLE_LOW_POWER_STOP);
+}
+
+static void omap2_apll_deny_idle(struct clk_hw_omap *clk)
+{
+	omap2_apll_set_autoidle(clk, OMAP2_APLL_AUTOIDLE_DISABLE);
+}
+
+static struct clk_hw_omap_ops omap2_apll_hwops = {
+	.allow_idle	= &omap2_apll_allow_idle,
+	.deny_idle	= &omap2_apll_deny_idle,
+};
+
+static void __init of_omap2_apll_setup(struct device_node *node)
+{
+	struct dpll_data *ad = NULL;
+	struct clk_hw_omap *clk_hw = NULL;
+	struct clk_init_data *init = NULL;
+	struct clk *clk;
+	const char *parent_name;
+	u32 val;
+
+	ad = kzalloc(sizeof(*clk_hw), GFP_KERNEL);
+	clk_hw = kzalloc(sizeof(*clk_hw), GFP_KERNEL);
+	init = kzalloc(sizeof(*init), GFP_KERNEL);
+
+	if (!ad || !clk_hw || !init)
+		goto cleanup;
+
+	clk_hw->dpll_data = ad;
+	clk_hw->hw.init = init;
+	init->ops = &omap2_apll_ops;
+	init->name = node->name;
+	clk_hw->ops = &omap2_apll_hwops;
+
+	init->num_parents = of_clk_get_parent_count(node);
+	if (init->num_parents != 1) {
+		pr_err("%s must have one parent\n", node->name);
+		goto cleanup;
+	}
+
+	parent_name = of_clk_get_parent_name(node, 0);
+	init->parent_names = &parent_name;
+
+	if (of_property_read_u32(node, "ti,clock-frequency", &val)) {
+		pr_err("%s missing clock-frequency\n", node->name);
+		goto cleanup;
+	}
+	clk_hw->fixed_rate = val;
+
+	if (of_property_read_u32(node, "ti,bit-shift", &val)) {
+		pr_err("%s missing bit-shift\n", node->name);
+		goto cleanup;
+	}
+
+	clk_hw->enable_bit = val;
+	ad->enable_mask = 0x3 << val;
+	ad->autoidle_mask = 0x3 << val;
+
+	if (of_property_read_u32(node, "ti,idlest-shift", &val)) {
+		pr_err("%s missing idlest-shift\n", node->name);
+		goto cleanup;
+	}
+
+	ad->idlest_mask = 1 << val;
+
+	ad->control_reg = ti_clk_get_reg_addr(node, 0);
+	ad->autoidle_reg = ti_clk_get_reg_addr(node, 1);
+	ad->idlest_reg = ti_clk_get_reg_addr(node, 2);
+
+	if (!ad->control_reg || !ad->autoidle_reg || !ad->idlest_reg)
+		goto cleanup;
+
+	clk = clk_register(NULL, &clk_hw->hw);
+	if (!IS_ERR(clk)) {
+		of_clk_add_provider(node, of_clk_src_simple_get, clk);
+		kfree(init);
+		return;
+	}
+cleanup:
+	kfree(clk_hw);
+	kfree(init);
+}
+CLK_OF_DECLARE(omap2_apll_clock, "ti,omap2-apll-clock",
+	       of_omap2_apll_setup);
diff --git a/include/linux/clk/ti.h b/include/linux/clk/ti.h
index 2310adc..ddac0d0 100644
--- a/include/linux/clk/ti.h
+++ b/include/linux/clk/ti.h
@@ -94,7 +94,26 @@ struct dpll_data {
 	u8			flags;
 };
 
-struct clk_hw_omap_ops;
+struct clk_hw_omap;
+
+/**
+ * struct clk_hw_omap_ops - OMAP clk ops
+ * @find_idlest: find idlest register information for a clock
+ * @find_companion: find companion clock register information for a clock,
+ *		    basically converts CM_ICLKEN* <-> CM_FCLKEN*
+ * @allow_idle: enables autoidle hardware functionality for a clock
+ * @deny_idle: prevent autoidle hardware functionality for a clock
+ */
+struct clk_hw_omap_ops {
+	void	(*find_idlest)(struct clk_hw_omap *oclk,
+			void __iomem **idlest_reg,
+			u8 *idlest_bit, u8 *idlest_val);
+	void	(*find_companion)(struct clk_hw_omap *oclk,
+			void __iomem **other_reg,
+			u8 *other_bit);
+	void	(*allow_idle)(struct clk_hw_omap *oclk);
+	void	(*deny_idle)(struct clk_hw_omap *oclk);
+};
 
 /**
  * struct clk_hw_omap - OMAP struct clk
-- 
1.7.9.5
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