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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright (C) 2014 Free Electrons4 *5 * Author: Boris BREZILLON <boris.brezillon@free-electrons.com>6 *7 * Allwinner A31 AR100 clock driver8 */9 10#include <linux/bitops.h>11#include <linux/clk-provider.h>12#include <linux/init.h>13#include <linux/of.h>14#include <linux/platform_device.h>15#include <linux/spinlock.h>16 17#include "clk-factors.h"18 19/*20 * sun6i_get_ar100_factors - Calculates factors p, m for AR10021 *22 * AR100 rate is calculated as follows23 * rate = (parent_rate >> p) / (m + 1);24 */25static void sun6i_get_ar100_factors(struct factors_request *req)26{27 unsigned long div;28 int shift;29 30 /* clock only divides */31 if (req->rate > req->parent_rate)32 req->rate = req->parent_rate;33 34 div = DIV_ROUND_UP(req->parent_rate, req->rate);35 36 if (div < 32)37 shift = 0;38 else if (div >> 1 < 32)39 shift = 1;40 else if (div >> 2 < 32)41 shift = 2;42 else43 shift = 3;44 45 div >>= shift;46 47 if (div > 32)48 div = 32;49 50 req->rate = (req->parent_rate >> shift) / div;51 req->m = div - 1;52 req->p = shift;53}54 55static const struct clk_factors_config sun6i_ar100_config = {56 .mwidth = 5,57 .mshift = 8,58 .pwidth = 2,59 .pshift = 4,60};61 62static const struct factors_data sun6i_ar100_data = {63 .mux = 16,64 .muxmask = GENMASK(1, 0),65 .table = &sun6i_ar100_config,66 .getter = sun6i_get_ar100_factors,67};68 69static DEFINE_SPINLOCK(sun6i_ar100_lock);70 71static int sun6i_a31_ar100_clk_probe(struct platform_device *pdev)72{73 struct device_node *np = pdev->dev.of_node;74 void __iomem *reg;75 struct clk *clk;76 77 reg = devm_platform_ioremap_resource(pdev, 0);78 if (IS_ERR(reg))79 return PTR_ERR(reg);80 81 clk = sunxi_factors_register(np, &sun6i_ar100_data, &sun6i_ar100_lock,82 reg);83 if (!clk)84 return -ENOMEM;85 86 platform_set_drvdata(pdev, clk);87 88 return 0;89}90 91static const struct of_device_id sun6i_a31_ar100_clk_dt_ids[] = {92 { .compatible = "allwinner,sun6i-a31-ar100-clk" },93 { /* sentinel */ }94};95 96static struct platform_driver sun6i_a31_ar100_clk_driver = {97 .driver = {98 .name = "sun6i-a31-ar100-clk",99 .of_match_table = sun6i_a31_ar100_clk_dt_ids,100 .suppress_bind_attrs = true,101 },102 .probe = sun6i_a31_ar100_clk_probe,103};104builtin_platform_driver(sun6i_a31_ar100_clk_driver);105