diff options
author | Mike Turquette <mturquette@linaro.org> | 2012-03-16 06:11:20 (GMT) |
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committer | Arnd Bergmann <arnd@arndb.de> | 2012-03-16 20:35:02 (GMT) |
commit | 9d9f78ed9af0e465d2fd15550471956e7f559b9f (patch) | |
tree | 8a65fc0844a35c928162f65b671a8a5786ea03ee /drivers/clk/clk-fixed-rate.c | |
parent | b2476490ef11134b65544d8f062cff96c53e941b (diff) | |
download | linux-fsl-qoriq-9d9f78ed9af0e465d2fd15550471956e7f559b9f.tar.xz |
clk: basic clock hardware types
Many platforms support simple gateable clocks, fixed-rate clocks,
adjustable divider clocks and multi-parent multiplexer clocks.
This patch introduces basic clock types for the above-mentioned hardware
which share some common characteristics.
Based on original work by Jeremy Kerr and contribution by Jamie Iles.
Dividers and multiplexor clocks originally contributed by Richard Zhao &
Sascha Hauer.
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Mike Turquette <mturquette@ti.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Rob Herring <rob.herring@calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Jeremy Kerr <jeremy.kerr@canonical.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergman <arnd.bergmann@linaro.org>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Shawn Guo <shawn.guo@freescale.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Jamie Iles <jamie@jamieiles.com>
Cc: Richard Zhao <richard.zhao@linaro.org>
Cc: Saravana Kannan <skannan@codeaurora.org>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Amit Kucheria <amit.kucheria@linaro.org>
Cc: Deepak Saxena <dsaxena@linaro.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'drivers/clk/clk-fixed-rate.c')
-rw-r--r-- | drivers/clk/clk-fixed-rate.c | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/drivers/clk/clk-fixed-rate.c b/drivers/clk/clk-fixed-rate.c new file mode 100644 index 0000000..90c79fb --- /dev/null +++ b/drivers/clk/clk-fixed-rate.c @@ -0,0 +1,82 @@ +/* + * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com> + * Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <mturquette@linaro.org> + * + * 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. + * + * Fixed rate clock implementation + */ + +#include <linux/clk-provider.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/io.h> +#include <linux/err.h> + +/* + * DOC: basic fixed-rate clock that cannot gate + * + * Traits of this clock: + * prepare - clk_(un)prepare only ensures parents are prepared + * enable - clk_enable only ensures parents are enabled + * rate - rate is always a fixed value. No clk_set_rate support + * parent - fixed parent. No clk_set_parent support + */ + +#define to_clk_fixed_rate(_hw) container_of(_hw, struct clk_fixed_rate, hw) + +static unsigned long clk_fixed_rate_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + return to_clk_fixed_rate(hw)->fixed_rate; +} +EXPORT_SYMBOL_GPL(clk_fixed_rate_recalc_rate); + +struct clk_ops clk_fixed_rate_ops = { + .recalc_rate = clk_fixed_rate_recalc_rate, +}; +EXPORT_SYMBOL_GPL(clk_fixed_rate_ops); + +struct clk *clk_register_fixed_rate(struct device *dev, const char *name, + const char *parent_name, unsigned long flags, + unsigned long fixed_rate) +{ + struct clk_fixed_rate *fixed; + char **parent_names = NULL; + u8 len; + + fixed = kzalloc(sizeof(struct clk_fixed_rate), GFP_KERNEL); + + if (!fixed) { + pr_err("%s: could not allocate fixed clk\n", __func__); + return ERR_PTR(-ENOMEM); + } + + /* struct clk_fixed_rate assignments */ + fixed->fixed_rate = fixed_rate; + + if (parent_name) { + parent_names = kmalloc(sizeof(char *), GFP_KERNEL); + + if (! parent_names) + goto out; + + len = sizeof(char) * strlen(parent_name); + + parent_names[0] = kmalloc(len, GFP_KERNEL); + + if (!parent_names[0]) + goto out; + + strncpy(parent_names[0], parent_name, len); + } + +out: + return clk_register(dev, name, + &clk_fixed_rate_ops, &fixed->hw, + parent_names, + (parent_name ? 1 : 0), + flags); +} |