diff options
author | Pawel Moll <pawel.moll@arm.com> | 2012-09-18 15:17:47 +0100 |
---|---|---|
committer | Mike Turquette <mturquette@linaro.org> | 2012-10-29 11:07:51 -0700 |
commit | ed27ff1db869cc81a92bed6defb7d107f5a156ff (patch) | |
tree | 635223b21f41fbda49ce9fc917ce5334574f59f9 /drivers/clk/versatile/clk-vexpress-osc.c | |
parent | f9f8c0438da2c6d6a4cd8af73097add3850d6084 (diff) |
clk: Versatile Express clock generators ("osc") driver
This driver provides a common clock framework hardware driver
for Versatile Express clock generators (a.k.a "osc") controlled
via the config bus.
Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Diffstat (limited to 'drivers/clk/versatile/clk-vexpress-osc.c')
-rw-r--r-- | drivers/clk/versatile/clk-vexpress-osc.c | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/drivers/clk/versatile/clk-vexpress-osc.c b/drivers/clk/versatile/clk-vexpress-osc.c new file mode 100644 index 000000000000..dcb6ae0a0425 --- /dev/null +++ b/drivers/clk/versatile/clk-vexpress-osc.c @@ -0,0 +1,146 @@ +/* + * 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. + * + * 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. + * + * Copyright (C) 2012 ARM Limited + */ + +#define pr_fmt(fmt) "vexpress-osc: " fmt + +#include <linux/clkdev.h> +#include <linux/clk-provider.h> +#include <linux/err.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/vexpress.h> + +struct vexpress_osc { + struct vexpress_config_func *func; + struct clk_hw hw; + unsigned long rate_min; + unsigned long rate_max; +}; + +#define to_vexpress_osc(osc) container_of(osc, struct vexpress_osc, hw) + +static unsigned long vexpress_osc_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct vexpress_osc *osc = to_vexpress_osc(hw); + u32 rate; + + vexpress_config_read(osc->func, 0, &rate); + + return rate; +} + +static long vexpress_osc_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + struct vexpress_osc *osc = to_vexpress_osc(hw); + + if (WARN_ON(osc->rate_min && rate < osc->rate_min)) + rate = osc->rate_min; + + if (WARN_ON(osc->rate_max && rate > osc->rate_max)) + rate = osc->rate_max; + + return rate; +} + +static int vexpress_osc_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct vexpress_osc *osc = to_vexpress_osc(hw); + + return vexpress_config_write(osc->func, 0, rate); +} + +static struct clk_ops vexpress_osc_ops = { + .recalc_rate = vexpress_osc_recalc_rate, + .round_rate = vexpress_osc_round_rate, + .set_rate = vexpress_osc_set_rate, +}; + + +struct clk * __init vexpress_osc_setup(struct device *dev) +{ + struct clk_init_data init; + struct vexpress_osc *osc = kzalloc(sizeof(*osc), GFP_KERNEL); + + if (!osc) + return NULL; + + osc->func = vexpress_config_func_get_by_dev(dev); + if (!osc->func) { + kfree(osc); + return NULL; + } + + init.name = dev_name(dev); + init.ops = &vexpress_osc_ops; + init.flags = CLK_IS_ROOT; + init.num_parents = 0; + osc->hw.init = &init; + + return clk_register(NULL, &osc->hw); +} + +void __init vexpress_osc_of_setup(struct device_node *node) +{ + struct clk_init_data init; + struct vexpress_osc *osc; + struct clk *clk; + u32 range[2]; + + osc = kzalloc(sizeof(*osc), GFP_KERNEL); + if (!osc) + goto error; + + osc->func = vexpress_config_func_get_by_node(node); + if (!osc->func) { + pr_err("Failed to obtain config func for node '%s'!\n", + node->name); + goto error; + } + + if (of_property_read_u32_array(node, "freq-range", range, + ARRAY_SIZE(range)) == 0) { + osc->rate_min = range[0]; + osc->rate_max = range[1]; + } + + of_property_read_string(node, "clock-output-names", &init.name); + if (!init.name) + init.name = node->name; + + init.ops = &vexpress_osc_ops; + init.flags = CLK_IS_ROOT; + init.num_parents = 0; + + osc->hw.init = &init; + + clk = clk_register(NULL, &osc->hw); + if (IS_ERR(clk)) { + pr_err("Failed to register clock '%s'!\n", init.name); + goto error; + } + + of_clk_add_provider(node, of_clk_src_simple_get, clk); + + pr_debug("Registered clock '%s'\n", init.name); + + return; + +error: + if (osc->func) + vexpress_config_func_put(osc->func); + kfree(osc); +} |