diff options
Diffstat (limited to 'drivers/clk/sunxi/clk-sun6i-ar100.c')
-rw-r--r-- | drivers/clk/sunxi/clk-sun6i-ar100.c | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/drivers/clk/sunxi/clk-sun6i-ar100.c b/drivers/clk/sunxi/clk-sun6i-ar100.c new file mode 100644 index 000000000..e1b7d0929 --- /dev/null +++ b/drivers/clk/sunxi/clk-sun6i-ar100.c @@ -0,0 +1,106 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2014 Free Electrons + * + * Author: Boris BREZILLON <boris.brezillon@free-electrons.com> + * + * Allwinner A31 AR100 clock driver + */ + +#include <linux/bitops.h> +#include <linux/clk-provider.h> +#include <linux/init.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/spinlock.h> + +#include "clk-factors.h" + +/** + * sun6i_get_ar100_factors - Calculates factors p, m for AR100 + * + * AR100 rate is calculated as follows + * rate = (parent_rate >> p) / (m + 1); + */ +static void sun6i_get_ar100_factors(struct factors_request *req) +{ + unsigned long div; + int shift; + + /* clock only divides */ + if (req->rate > req->parent_rate) + req->rate = req->parent_rate; + + div = DIV_ROUND_UP(req->parent_rate, req->rate); + + if (div < 32) + shift = 0; + else if (div >> 1 < 32) + shift = 1; + else if (div >> 2 < 32) + shift = 2; + else + shift = 3; + + div >>= shift; + + if (div > 32) + div = 32; + + req->rate = (req->parent_rate >> shift) / div; + req->m = div - 1; + req->p = shift; +} + +static const struct clk_factors_config sun6i_ar100_config = { + .mwidth = 5, + .mshift = 8, + .pwidth = 2, + .pshift = 4, +}; + +static const struct factors_data sun6i_ar100_data = { + .mux = 16, + .muxmask = GENMASK(1, 0), + .table = &sun6i_ar100_config, + .getter = sun6i_get_ar100_factors, +}; + +static DEFINE_SPINLOCK(sun6i_ar100_lock); + +static int sun6i_a31_ar100_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 = sunxi_factors_register(np, &sun6i_ar100_data, &sun6i_ar100_lock, + reg); + if (!clk) + return -ENOMEM; + + platform_set_drvdata(pdev, clk); + + return 0; +} + +static const struct of_device_id sun6i_a31_ar100_clk_dt_ids[] = { + { .compatible = "allwinner,sun6i-a31-ar100-clk" }, + { /* sentinel */ } +}; + +static struct platform_driver sun6i_a31_ar100_clk_driver = { + .driver = { + .name = "sun6i-a31-ar100-clk", + .of_match_table = sun6i_a31_ar100_clk_dt_ids, + .suppress_bind_attrs = true, + }, + .probe = sun6i_a31_ar100_clk_probe, +}; +builtin_platform_driver(sun6i_a31_ar100_clk_driver); |