[U-Boot] [PATCH 03/11] ARM: AM43xx: Add support for disabling clocks in uboot

[Vignesh R]

From: Kishon Vijay Abraham I <kishon at ti.com>

Add do_disable_clocks() to disable clock domains and module clocks.
These clocks are enabled using do_enable_clocks().

Signed-off-by: Kishon Vijay Abraham I <kishon at ti.com>
Signed-off-by: Vignesh R <vigneshr at ti.com>
---
 arch/arm/cpu/armv7/am33xx/clock.c        | 52 ++++++++++++++++++++++++++++++++
 arch/arm/include/asm/arch-am33xx/clock.h |  1 +
 2 files changed, 53 insertions(+)

diff --git a/arch/arm/cpu/armv7/am33xx/clock.c b/arch/arm/cpu/armv7/am33xx/clock.c
index ec7d46838b74..595c951ed245 100644
--- a/arch/arm/cpu/armv7/am33xx/clock.c
+++ b/arch/arm/cpu/armv7/am33xx/clock.c
@@ -144,6 +144,33 @@ static inline void enable_clock_module(u32 *const clkctrl_addr, u32 enable_mode,
 		wait_for_clk_enable(clkctrl_addr);
 }
 
+static inline void wait_for_clk_disable(u32 *clkctrl_addr)
+{
+	u32 clkctrl, idlest = MODULE_CLKCTRL_IDLEST_FULLY_FUNCTIONAL;
+	u32 bound = LDELAY;
+
+	while ((idlest != MODULE_CLKCTRL_IDLEST_DISABLED)) {
+		clkctrl = readl(clkctrl_addr);
+		idlest = (clkctrl & MODULE_CLKCTRL_IDLEST_MASK) >>
+			  MODULE_CLKCTRL_IDLEST_SHIFT;
+		if (--bound == 0) {
+			printf("Clock disable failed for 0x%p idlest 0x%x\n",
+			       clkctrl_addr, clkctrl);
+			 return;
+		}
+	}
+}
+static inline void disable_clock_module(u32 *const clkctrl_addr,
+					u32 wait_for_disable)
+{
+	clrsetbits_le32(clkctrl_addr, MODULE_CLKCTRL_MODULEMODE_MASK,
+			MODULE_CLKCTRL_MODULEMODE_SW_DISABLE <<
+			MODULE_CLKCTRL_MODULEMODE_SHIFT);
+	debug("Disable clock module - %p\n", clkctrl_addr);
+	if (wait_for_disable)
+		wait_for_clk_disable(clkctrl_addr);
+}
+
 static inline void enable_clock_domain(u32 *const clkctrl_reg, u32 enable_mode)
 {
 	clrsetbits_le32(clkctrl_reg, CD_CLKCTRL_CLKTRCTRL_MASK,
@@ -151,6 +178,14 @@ static inline void enable_clock_domain(u32 *const clkctrl_reg, u32 enable_mode)
 	debug("Enable clock domain - %p\n", clkctrl_reg);
 }
 
+static inline void disable_clock_domain(u32 *const clkctrl_reg)
+{
+	clrsetbits_le32(clkctrl_reg, CD_CLKCTRL_CLKTRCTRL_MASK,
+			CD_CLKCTRL_CLKTRCTRL_SW_SLEEP <<
+			CD_CLKCTRL_CLKTRCTRL_SHIFT);
+	debug("Disable clock domain - %p\n", clkctrl_reg);
+}
+
 void do_enable_clocks(u32 *const *clk_domains,
 		      u32 *const *clk_modules_explicit_en, u8 wait_for_enable)
 {
@@ -170,6 +205,23 @@ void do_enable_clocks(u32 *const *clk_domains,
 	};
 }
 
+void do_disable_clocks(u32 *const *clk_domains,
+			u32 *const *clk_modules_disable,
+			u8 wait_for_disable)
+{
+	u32 i, max = 100;
+
+
+	/* Clock modules that need to be put in SW_DISABLE */
+	for (i = 0; (i < max) && clk_modules_disable[i]; i++)
+		disable_clock_module(clk_modules_disable[i],
+				     wait_for_disable);
+
+	/* Put the clock domains in SW_SLEEP mode */
+	for (i = 0; (i < max) && clk_domains[i]; i++)
+		disable_clock_domain(clk_domains[i]);
+}
+
 /*
  * Before scaling up the clocks we need to have the PMIC scale up the
  * voltages first.  This will be dependent on which PMIC is in use
diff --git a/arch/arm/include/asm/arch-am33xx/clock.h b/arch/arm/include/asm/arch-am33xx/clock.h
index 4af6b57e42f5..a6d2419fb843 100644
--- a/arch/arm/include/asm/arch-am33xx/clock.h
+++ b/arch/arm/include/asm/arch-am33xx/clock.h
@@ -112,5 +112,6 @@ void do_setup_dpll(const struct dpll_regs *, const struct dpll_params *);
 void prcm_init(void);
 void enable_basic_clocks(void);
 void do_enable_clocks(u32 *const *, u32 *const *, u8);
+void do_disable_clocks(u32 *const *, u32 *const *, u8);
 
 #endif
-- 
2.4.5