diff options
author | Boris BREZILLON <boris.brezillon@free-electrons.com> | 2014-05-15 12:55:11 +0400 |
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committer | Maxime Ripard <maxime.ripard@free-electrons.com> | 2014-06-11 12:25:02 +0400 |
commit | c8a76cac19eebf65f629e3676e57743f9dfeea8f (patch) | |
tree | 3988645d9fe86f15009e324b8e0ac575d2c27d7d /drivers/clk/sunxi/clk-sun6i-apb0.c | |
parent | efb3184c08927c54ed984c85f69f54ff1dbd2c37 (diff) | |
download | linux-c8a76cac19eebf65f629e3676e57743f9dfeea8f.tar.xz |
clk: sunxi: add PRCM (Power/Reset/Clock Management) clks support
The PRCM (Power/Reset/Clock Management) unit provides several clock
devices:
- AR100 clk: used to clock the Power Management co-processor
- AHB0 clk: used to clock the AHB0 bus
- APB0 clk and gates: used to clk peripherals connected to the APB0 bus
Add support for these clks in a separate driver so that they can be probed
as platform devices instead of registered during early init.
This is needed to be able to probe PRCM MFD subdevices.
Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Emilio López <emilio@elopez.com.ar>
Diffstat (limited to 'drivers/clk/sunxi/clk-sun6i-apb0.c')
-rw-r--r-- | drivers/clk/sunxi/clk-sun6i-apb0.c | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/drivers/clk/sunxi/clk-sun6i-apb0.c b/drivers/clk/sunxi/clk-sun6i-apb0.c new file mode 100644 index 000000000000..11f17c34c2ae --- /dev/null +++ b/drivers/clk/sunxi/clk-sun6i-apb0.c @@ -0,0 +1,77 @@ +/* + * Copyright (C) 2014 Free Electrons + * + * License Terms: GNU General Public License v2 + * Author: Boris BREZILLON <boris.brezillon@free-electrons.com> + * + * Allwinner A31 APB0 clock driver + * + */ + +#include <linux/clk-provider.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> + +/* + * The APB0 clk has a configurable divisor. + * + * We must use a clk_div_table and not a regular power of 2 + * divisor here, because the first 2 values divide the clock + * by 2. + */ +static const struct clk_div_table sun6i_a31_apb0_divs[] = { + { .val = 0, .div = 2, }, + { .val = 1, .div = 2, }, + { .val = 2, .div = 4, }, + { .val = 3, .div = 8, }, + { /* sentinel */ }, +}; + +static int sun6i_a31_apb0_clk_probe(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + const char *clk_name = np->name; + const char *clk_parent; + struct resource *r; + void __iomem *reg; + struct clk *clk; + + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + reg = devm_ioremap_resource(&pdev->dev, r); + if (IS_ERR(reg)) + return PTR_ERR(reg); + + clk_parent = of_clk_get_parent_name(np, 0); + if (!clk_parent) + return -EINVAL; + + of_property_read_string(np, "clock-output-names", &clk_name); + + clk = clk_register_divider_table(&pdev->dev, clk_name, clk_parent, + 0, reg, 0, 2, 0, sun6i_a31_apb0_divs, + NULL); + if (IS_ERR(clk)) + return PTR_ERR(clk); + + return of_clk_add_provider(np, of_clk_src_simple_get, clk); +} + +const struct of_device_id sun6i_a31_apb0_clk_dt_ids[] = { + { .compatible = "allwinner,sun6i-a31-apb0-clk" }, + { /* sentinel */ } +}; + +static struct platform_driver sun6i_a31_apb0_clk_driver = { + .driver = { + .name = "sun6i-a31-apb0-clk", + .owner = THIS_MODULE, + .of_match_table = sun6i_a31_apb0_clk_dt_ids, + }, + .probe = sun6i_a31_apb0_clk_probe, +}; +module_platform_driver(sun6i_a31_apb0_clk_driver); + +MODULE_AUTHOR("Boris BREZILLON <boris.brezillon@free-electrons.com>"); +MODULE_DESCRIPTION("Allwinner A31 APB0 clock Driver"); +MODULE_LICENSE("GPL v2"); |