diff options
Diffstat (limited to 'drivers/clk/sunxi/clk-sun8i-apb0.c')
-rw-r--r-- | drivers/clk/sunxi/clk-sun8i-apb0.c | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/drivers/clk/sunxi/clk-sun8i-apb0.c b/drivers/clk/sunxi/clk-sun8i-apb0.c new file mode 100644 index 000000000..d5c31804e --- /dev/null +++ b/drivers/clk/sunxi/clk-sun8i-apb0.c @@ -0,0 +1,116 @@ +/* + * Copyright (C) 2014 Chen-Yu Tsai + * Author: Chen-Yu Tsai <wens@csie.org> + * + * Allwinner A23 APB0 clock driver + * + * License Terms: GNU General Public License v2 + * + * Based on clk-sun6i-apb0.c + * Allwinner A31 APB0 clock driver + * + * Copyright (C) 2014 Free Electrons + * Author: Boris BREZILLON <boris.brezillon@free-electrons.com> + * + */ + +#include <linux/clk-provider.h> +#include <linux/init.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/platform_device.h> + +static struct clk *sun8i_a23_apb0_register(struct device_node *node, + void __iomem *reg) +{ + const char *clk_name = node->name; + const char *clk_parent; + struct clk *clk; + int ret; + + clk_parent = of_clk_get_parent_name(node, 0); + if (!clk_parent) + return ERR_PTR(-EINVAL); + + of_property_read_string(node, "clock-output-names", &clk_name); + + /* The A23 APB0 clock is a standard 2 bit wide divider clock */ + clk = clk_register_divider(NULL, clk_name, clk_parent, 0, reg, + 0, 2, 0, NULL); + if (IS_ERR(clk)) + return clk; + + ret = of_clk_add_provider(node, of_clk_src_simple_get, clk); + if (ret) + goto err_unregister; + + return clk; + +err_unregister: + clk_unregister_divider(clk); + + return ERR_PTR(ret); +} + +static void sun8i_a23_apb0_setup(struct device_node *node) +{ + void __iomem *reg; + struct resource res; + struct clk *clk; + + reg = of_io_request_and_map(node, 0, of_node_full_name(node)); + if (IS_ERR(reg)) { + /* + * This happens with clk nodes instantiated through mfd, + * as those do not have their resources assigned in the + * device tree. Do not print an error in this case. + */ + if (PTR_ERR(reg) != -EINVAL) + pr_err("Could not get registers for a23-apb0-clk\n"); + + return; + } + + clk = sun8i_a23_apb0_register(node, reg); + if (IS_ERR(clk)) + goto err_unmap; + + return; + +err_unmap: + iounmap(reg); + of_address_to_resource(node, 0, &res); + release_mem_region(res.start, resource_size(&res)); +} +CLK_OF_DECLARE_DRIVER(sun8i_a23_apb0, "allwinner,sun8i-a23-apb0-clk", + sun8i_a23_apb0_setup); + +static int sun8i_a23_apb0_clk_probe(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + 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 = sun8i_a23_apb0_register(np, reg); + return PTR_ERR_OR_ZERO(clk); +} + +static const struct of_device_id sun8i_a23_apb0_clk_dt_ids[] = { + { .compatible = "allwinner,sun8i-a23-apb0-clk" }, + { /* sentinel */ } +}; + +static struct platform_driver sun8i_a23_apb0_clk_driver = { + .driver = { + .name = "sun8i-a23-apb0-clk", + .of_match_table = sun8i_a23_apb0_clk_dt_ids, + }, + .probe = sun8i_a23_apb0_clk_probe, +}; +builtin_platform_driver(sun8i_a23_apb0_clk_driver); |