diff options
Diffstat (limited to 'kernel/drivers/clk/versatile/clk-vexpress-osc.c')
-rw-r--r-- | kernel/drivers/clk/versatile/clk-vexpress-osc.c | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/kernel/drivers/clk/versatile/clk-vexpress-osc.c b/kernel/drivers/clk/versatile/clk-vexpress-osc.c new file mode 100644 index 000000000..89c0609e1 --- /dev/null +++ b/kernel/drivers/clk/versatile/clk-vexpress-osc.c @@ -0,0 +1,130 @@ +/* + * 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 + */ + +#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 regmap *reg; + 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; + + regmap_read(osc->reg, 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 regmap_write(osc->reg, 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, +}; + + +static int vexpress_osc_probe(struct platform_device *pdev) +{ + struct clk_init_data init; + struct vexpress_osc *osc; + struct clk *clk; + u32 range[2]; + + osc = devm_kzalloc(&pdev->dev, sizeof(*osc), GFP_KERNEL); + if (!osc) + return -ENOMEM; + + osc->reg = devm_regmap_init_vexpress_config(&pdev->dev); + if (IS_ERR(osc->reg)) + return PTR_ERR(osc->reg); + + if (of_property_read_u32_array(pdev->dev.of_node, "freq-range", range, + ARRAY_SIZE(range)) == 0) { + osc->rate_min = range[0]; + osc->rate_max = range[1]; + } + + if (of_property_read_string(pdev->dev.of_node, "clock-output-names", + &init.name) != 0) + init.name = dev_name(&pdev->dev); + + 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)) + return PTR_ERR(clk); + + of_clk_add_provider(pdev->dev.of_node, of_clk_src_simple_get, clk); + + dev_dbg(&pdev->dev, "Registered clock '%s'\n", init.name); + + return 0; +} + +static const struct of_device_id vexpress_osc_of_match[] = { + { .compatible = "arm,vexpress-osc", }, + {} +}; + +static struct platform_driver vexpress_osc_driver = { + .driver = { + .name = "vexpress-osc", + .of_match_table = vexpress_osc_of_match, + }, + .probe = vexpress_osc_probe, +}; + +static int __init vexpress_osc_init(void) +{ + return platform_driver_register(&vexpress_osc_driver); +} +core_initcall(vexpress_osc_init); |