diff options
author | Maxime Ripard <maxime.ripard@free-electrons.com> | 2016-06-29 21:05:24 +0200 |
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committer | Michael Turquette <mturquette@baylibre.com> | 2016-07-08 18:04:35 -0700 |
commit | 89a3dfb787072438f72de95ff3fe7b58213e08c1 (patch) | |
tree | daf43053478fb5cf05282b4fbfd534dc083d66a3 /drivers/clk | |
parent | 1d80c14248d6082c91a8a9e3d70cc94c3cc18ecb (diff) | |
download | linux-stable-89a3dfb787072438f72de95ff3fe7b58213e08c1.tar.gz linux-stable-89a3dfb787072438f72de95ff3fe7b58213e08c1.tar.bz2 linux-stable-89a3dfb787072438f72de95ff3fe7b58213e08c1.zip |
clk: sunxi-ng: Add fractional lib
Some clocks can be switched to a mode called fractional that have two fixed
output rate you can choose from.
Add a small library to deal with those clocks.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20160629190535.11855-4-maxime.ripard@free-electrons.com
Diffstat (limited to 'drivers/clk')
-rw-r--r-- | drivers/clk/sunxi-ng/Kconfig | 9 | ||||
-rw-r--r-- | drivers/clk/sunxi-ng/Makefile | 3 | ||||
-rw-r--r-- | drivers/clk/sunxi-ng/ccu_frac.c | 110 | ||||
-rw-r--r-- | drivers/clk/sunxi-ng/ccu_frac.h | 53 |
4 files changed, 175 insertions, 0 deletions
diff --git a/drivers/clk/sunxi-ng/Kconfig b/drivers/clk/sunxi-ng/Kconfig index df5b2768d8b4..3d117d7a3621 100644 --- a/drivers/clk/sunxi-ng/Kconfig +++ b/drivers/clk/sunxi-ng/Kconfig @@ -1,3 +1,12 @@ config SUNXI_CCU bool "Clock support for Allwinner SoCs" default ARCH_SUNXI + +if SUNXI_CCU + +# Base clock types + +config SUNXI_CCU_FRAC + bool + +endif diff --git a/drivers/clk/sunxi-ng/Makefile b/drivers/clk/sunxi-ng/Makefile index 886d0786ca51..46f417cb682a 100644 --- a/drivers/clk/sunxi-ng/Makefile +++ b/drivers/clk/sunxi-ng/Makefile @@ -1,3 +1,6 @@ # Common objects obj-$(CONFIG_SUNXI_CCU) += ccu_common.o obj-$(CONFIG_SUNXI_CCU) += ccu_reset.o + +# Base clock types +obj-$(CONFIG_SUNXI_CCU_FRAC) += ccu_frac.o diff --git a/drivers/clk/sunxi-ng/ccu_frac.c b/drivers/clk/sunxi-ng/ccu_frac.c new file mode 100644 index 000000000000..5c4b10cd15b5 --- /dev/null +++ b/drivers/clk/sunxi-ng/ccu_frac.c @@ -0,0 +1,110 @@ +/* + * Copyright (C) 2016 Maxime Ripard + * Maxime Ripard <maxime.ripard@free-electrons.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + */ + +#include <linux/clk-provider.h> +#include <linux/spinlock.h> + +#include "ccu_frac.h" + +bool ccu_frac_helper_is_enabled(struct ccu_common *common, + struct _ccu_frac *cf) +{ + if (!(common->features & CCU_FEATURE_FRACTIONAL)) + return false; + + return !(readl(common->base + common->reg) & cf->enable); +} + +void ccu_frac_helper_enable(struct ccu_common *common, + struct _ccu_frac *cf) +{ + unsigned long flags; + u32 reg; + + if (!(common->features & CCU_FEATURE_FRACTIONAL)) + return; + + spin_lock_irqsave(common->lock, flags); + reg = readl(common->base + common->reg); + writel(reg & ~cf->enable, common->base + common->reg); + spin_unlock_irqrestore(common->lock, flags); +} + +void ccu_frac_helper_disable(struct ccu_common *common, + struct _ccu_frac *cf) +{ + unsigned long flags; + u32 reg; + + if (!(common->features & CCU_FEATURE_FRACTIONAL)) + return; + + spin_lock_irqsave(common->lock, flags); + reg = readl(common->base + common->reg); + writel(reg | cf->enable, common->base + common->reg); + spin_unlock_irqrestore(common->lock, flags); +} + +bool ccu_frac_helper_has_rate(struct ccu_common *common, + struct _ccu_frac *cf, + unsigned long rate) +{ + if (!(common->features & CCU_FEATURE_FRACTIONAL)) + return false; + + return (cf->rates[0] == rate) || (cf->rates[1] == rate); +} + +unsigned long ccu_frac_helper_read_rate(struct ccu_common *common, + struct _ccu_frac *cf) +{ + u32 reg; + + printk("%s: Read fractional\n", clk_hw_get_name(&common->hw)); + + if (!(common->features & CCU_FEATURE_FRACTIONAL)) + return 0; + + printk("%s: clock is fractional (rates %lu and %lu)\n", + clk_hw_get_name(&common->hw), cf->rates[0], cf->rates[1]); + + reg = readl(common->base + common->reg); + + printk("%s: clock reg is 0x%x (select is 0x%x)\n", + clk_hw_get_name(&common->hw), reg, cf->select); + + return (reg & cf->select) ? cf->rates[1] : cf->rates[0]; +} + +int ccu_frac_helper_set_rate(struct ccu_common *common, + struct _ccu_frac *cf, + unsigned long rate) +{ + unsigned long flags; + u32 reg, sel; + + if (!(common->features & CCU_FEATURE_FRACTIONAL)) + return -EINVAL; + + if (cf->rates[0] == rate) + sel = 0; + else if (cf->rates[1] == rate) + sel = cf->select; + else + return -EINVAL; + + spin_lock_irqsave(common->lock, flags); + reg = readl(common->base + common->reg); + reg &= ~cf->select; + writel(reg | sel, common->base + common->reg); + spin_unlock_irqrestore(common->lock, flags); + + return 0; +} diff --git a/drivers/clk/sunxi-ng/ccu_frac.h b/drivers/clk/sunxi-ng/ccu_frac.h new file mode 100644 index 000000000000..e4c670b1cdfe --- /dev/null +++ b/drivers/clk/sunxi-ng/ccu_frac.h @@ -0,0 +1,53 @@ +/* + * Copyright (c) 2016 Maxime Ripard. All rights reserved. + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#ifndef _CCU_FRAC_H_ +#define _CCU_FRAC_H_ + +#include <linux/clk-provider.h> + +#include "ccu_common.h" + +struct _ccu_frac { + u32 enable; + u32 select; + + unsigned long rates[2]; +}; + +#define _SUNXI_CCU_FRAC(_enable, _select, _rate1, _rate2) \ + { \ + .enable = _enable, \ + .select = _select, \ + .rates = { _rate1, _rate2 }, \ + } + +bool ccu_frac_helper_is_enabled(struct ccu_common *common, + struct _ccu_frac *cf); +void ccu_frac_helper_enable(struct ccu_common *common, + struct _ccu_frac *cf); +void ccu_frac_helper_disable(struct ccu_common *common, + struct _ccu_frac *cf); + +bool ccu_frac_helper_has_rate(struct ccu_common *common, + struct _ccu_frac *cf, + unsigned long rate); + +unsigned long ccu_frac_helper_read_rate(struct ccu_common *common, + struct _ccu_frac *cf); + +int ccu_frac_helper_set_rate(struct ccu_common *common, + struct _ccu_frac *cf, + unsigned long rate); + +#endif /* _CCU_FRAC_H_ */ |