On Tue, Oct 11, 2011 at 11:46 PM, Richard Zhao <richard.z...@freescale.com> wrote: > On Thu, Sep 22, 2011 at 03:26:59PM -0700, Mike Turquette wrote: >> From: Jeremy Kerr <jeremy.k...@canonical.com> >> >> Signed-off-by: Jeremy Kerr <jeremy.k...@canonical.com> >> Signed-off-by: Mark Brown <broo...@opensource.wolfsonmicro.com> >> Signed-off-by: Jamie Iles <ja...@jamieiles.com> >> Signed-off-by: Mike Turquette <mturque...@ti.com> >> --- >> Changes since v1: >> Add copyright header >> Fold in Jamie's patch for set-to-disable clks >> Use BIT macro instead of shift >> >> drivers/clk/Kconfig | 4 ++ >> drivers/clk/Makefile | 1 + >> drivers/clk/clk-gate.c | 78 >> ++++++++++++++++++++++++++++++++++++++++++++++++ >> include/linux/clk.h | 13 ++++++++ >> 4 files changed, 96 insertions(+), 0 deletions(-) >> create mode 100644 drivers/clk/clk-gate.c > > I feel hard to tell the tree the clk parent, at register/init time. For the > simple gate clk, the only way is to set .get_parent. But normally, for clk > without any divider we set .get_parent to NULL. Maybe we can put .parent to > struct clk_hw?
For non-mux clocks, whose parent is *always* going to be the same, you should create a duplicate .parent in the clk_hw_* structure and then have .get_parent return clk_hw_*->parent. This is analogous to the way clk_hw_fixed returns clk_hw_fixed->rate when .recalc is called on it. Regards, Mike > Thanks > Richard >> >> diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig >> index d8313d7..a78967c 100644 >> --- a/drivers/clk/Kconfig >> +++ b/drivers/clk/Kconfig >> @@ -12,3 +12,7 @@ config GENERIC_CLK >> config GENERIC_CLK_FIXED >> bool >> depends on GENERIC_CLK >> + >> +config GENERIC_CLK_GATE >> + bool >> + depends on GENERIC_CLK >> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile >> index 9a3325a..d186446 100644 >> --- a/drivers/clk/Makefile >> +++ b/drivers/clk/Makefile >> @@ -2,3 +2,4 @@ >> obj-$(CONFIG_CLKDEV_LOOKUP) += clkdev.o >> obj-$(CONFIG_GENERIC_CLK) += clk.o >> obj-$(CONFIG_GENERIC_CLK_FIXED) += clk-fixed.o >> +obj-$(CONFIG_GENERIC_CLK_GATE) += clk-gate.o >> diff --git a/drivers/clk/clk-gate.c b/drivers/clk/clk-gate.c >> new file mode 100644 >> index 0000000..a1d8e79 >> --- /dev/null >> +++ b/drivers/clk/clk-gate.c >> @@ -0,0 +1,78 @@ >> +/* >> + * Copyright (C) 2010-2011 Canonical Ltd <jeremy.k...@canonical.com> >> + * >> + * This program is free software; you can redistribute it and/or modify >> + * it under the terms of the GNU General Public License version 2 as >> + * published by the Free Software Foundation. >> + * >> + * Simple clk gate implementation >> + */ >> + >> +#include <linux/clk.h> >> +#include <linux/module.h> >> +#include <asm/io.h> >> + >> +#define to_clk_gate(clk) container_of(clk, struct clk_gate, hw) >> + >> +static unsigned long clk_gate_get_rate(struct clk_hw *clk) >> +{ >> + return clk_get_rate(clk_get_parent(clk->clk)); >> +} >> + >> +static void clk_gate_set_bit(struct clk_hw *clk) >> +{ >> + struct clk_gate *gate = to_clk_gate(clk); >> + u32 reg; >> + >> + reg = __raw_readl(gate->reg); >> + reg |= BIT(gate->bit_idx); >> + __raw_writel(reg, gate->reg); >> +} >> + >> +static void clk_gate_clear_bit(struct clk_hw *clk) >> +{ >> + struct clk_gate *gate = to_clk_gate(clk); >> + u32 reg; >> + >> + reg = __raw_readl(gate->reg); >> + reg &= ~BIT(gate->bit_idx); >> + __raw_writel(reg, gate->reg); >> +} >> + >> +static int clk_gate_enable_set(struct clk_hw *clk) >> +{ >> + clk_gate_set_bit(clk); >> + >> + return 0; >> +} >> + >> +static void clk_gate_disable_clear(struct clk_hw *clk) >> +{ >> + clk_gate_clear_bit(clk); >> +} >> + >> +struct clk_hw_ops clk_gate_set_enable_ops = { >> + .recalc_rate = clk_gate_get_rate, >> + .enable = clk_gate_enable_set, >> + .disable = clk_gate_disable_clear, >> +}; >> +EXPORT_SYMBOL_GPL(clk_gate_set_enable_ops); >> + >> +static int clk_gate_enable_clear(struct clk_hw *clk) >> +{ >> + clk_gate_clear_bit(clk); >> + >> + return 0; >> +} >> + >> +static void clk_gate_disable_set(struct clk_hw *clk) >> +{ >> + clk_gate_set_bit(clk); >> +} >> + >> +struct clk_hw_ops clk_gate_set_disable_ops = { >> + .recalc_rate = clk_gate_get_rate, >> + .enable = clk_gate_enable_clear, >> + .disable = clk_gate_disable_set, >> +}; >> +EXPORT_SYMBOL_GPL(clk_gate_set_disable_ops); >> diff --git a/include/linux/clk.h b/include/linux/clk.h >> index 1903dd8..626fd0d 100644 >> --- a/include/linux/clk.h >> +++ b/include/linux/clk.h >> @@ -124,6 +124,19 @@ extern struct clk_hw_ops clk_fixed_ops; >> >> #endif /* CONFIG_GENERIC_CLK_FIXED */ >> >> +#ifdef CONFIG_GENERIC_CLK_GATE >> + >> +struct clk_gate { >> + struct clk_hw hw; >> + void __iomem *reg; >> + u8 bit_idx; >> +}; >> + >> +extern struct clk_hw_ops clk_gate_set_enable_ops; >> +extern struct clk_hw_ops clk_gate_set_disable_ops; >> + >> +#endif /* CONFIG_GENERIC_CLK_GATE */ >> + >> /** >> * clk_register - register and initialize a new clock >> * >> -- >> 1.7.4.1 >> >> >> _______________________________________________ >> linux-arm-kernel mailing list >> linux-arm-ker...@lists.infradead.org >> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >> > > _______________________________________________ linaro-dev mailing list linaro-dev@lists.linaro.org http://lists.linaro.org/mailman/listinfo/linaro-dev