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1// SPDX-License-Identifier: GPL-2.0-only2/*3* TWL6040 clock module driver for OMAP4 McPDM functional clock4*5* Copyright (C) 2012 Texas Instruments Inc.6* Peter Ujfalusi <peter.ujfalusi@ti.com>7*/8 9#include <linux/module.h>10#include <linux/slab.h>11#include <linux/platform_device.h>12#include <linux/mfd/twl6040.h>13#include <linux/clk-provider.h>14 15struct twl6040_pdmclk {16 struct twl6040 *twl6040;17 struct device *dev;18 struct clk_hw pdmclk_hw;19 int enabled;20};21 22static int twl6040_pdmclk_is_prepared(struct clk_hw *hw)23{24 struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk,25 pdmclk_hw);26 27 return pdmclk->enabled;28}29 30static int twl6040_pdmclk_reset_one_clock(struct twl6040_pdmclk *pdmclk,31 unsigned int reg)32{33 const u8 reset_mask = TWL6040_HPLLRST; /* Same for HPPLL and LPPLL */34 int ret;35 36 ret = twl6040_set_bits(pdmclk->twl6040, reg, reset_mask);37 if (ret < 0)38 return ret;39 40 ret = twl6040_clear_bits(pdmclk->twl6040, reg, reset_mask);41 if (ret < 0)42 return ret;43 44 return 0;45}46 47/*48 * TWL6040A2 Phoenix Audio IC erratum #6: "PDM Clock Generation Issue At49 * Cold Temperature". This affects cold boot and deeper idle states it50 * seems. The workaround consists of resetting HPPLL and LPPLL.51 */52static int twl6040_pdmclk_quirk_reset_clocks(struct twl6040_pdmclk *pdmclk)53{54 int ret;55 56 ret = twl6040_pdmclk_reset_one_clock(pdmclk, TWL6040_REG_HPPLLCTL);57 if (ret)58 return ret;59 60 ret = twl6040_pdmclk_reset_one_clock(pdmclk, TWL6040_REG_LPPLLCTL);61 if (ret)62 return ret;63 64 return 0;65}66 67static int twl6040_pdmclk_prepare(struct clk_hw *hw)68{69 struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk,70 pdmclk_hw);71 int ret;72 73 ret = twl6040_power(pdmclk->twl6040, 1);74 if (ret)75 return ret;76 77 ret = twl6040_pdmclk_quirk_reset_clocks(pdmclk);78 if (ret)79 goto out_err;80 81 pdmclk->enabled = 1;82 83 return 0;84 85out_err:86 dev_err(pdmclk->dev, "%s: error %i\n", __func__, ret);87 twl6040_power(pdmclk->twl6040, 0);88 89 return ret;90}91 92static void twl6040_pdmclk_unprepare(struct clk_hw *hw)93{94 struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk,95 pdmclk_hw);96 int ret;97 98 ret = twl6040_power(pdmclk->twl6040, 0);99 if (!ret)100 pdmclk->enabled = 0;101 102}103 104static unsigned long twl6040_pdmclk_recalc_rate(struct clk_hw *hw,105 unsigned long parent_rate)106{107 struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk,108 pdmclk_hw);109 110 return twl6040_get_sysclk(pdmclk->twl6040);111}112 113static const struct clk_ops twl6040_pdmclk_ops = {114 .is_prepared = twl6040_pdmclk_is_prepared,115 .prepare = twl6040_pdmclk_prepare,116 .unprepare = twl6040_pdmclk_unprepare,117 .recalc_rate = twl6040_pdmclk_recalc_rate,118};119 120static const struct clk_init_data twl6040_pdmclk_init = {121 .name = "pdmclk",122 .ops = &twl6040_pdmclk_ops,123 .flags = CLK_GET_RATE_NOCACHE,124};125 126static int twl6040_pdmclk_probe(struct platform_device *pdev)127{128 struct twl6040 *twl6040 = dev_get_drvdata(pdev->dev.parent);129 struct twl6040_pdmclk *clkdata;130 int ret;131 132 clkdata = devm_kzalloc(&pdev->dev, sizeof(*clkdata), GFP_KERNEL);133 if (!clkdata)134 return -ENOMEM;135 136 clkdata->dev = &pdev->dev;137 clkdata->twl6040 = twl6040;138 139 clkdata->pdmclk_hw.init = &twl6040_pdmclk_init;140 ret = devm_clk_hw_register(&pdev->dev, &clkdata->pdmclk_hw);141 if (ret)142 return ret;143 144 platform_set_drvdata(pdev, clkdata);145 146 return devm_of_clk_add_hw_provider(&pdev->dev, of_clk_hw_simple_get,147 &clkdata->pdmclk_hw);148}149 150static struct platform_driver twl6040_pdmclk_driver = {151 .driver = {152 .name = "twl6040-pdmclk",153 },154 .probe = twl6040_pdmclk_probe,155};156 157module_platform_driver(twl6040_pdmclk_driver);158 159MODULE_DESCRIPTION("TWL6040 clock driver for McPDM functional clock");160MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");161MODULE_ALIAS("platform:twl6040-pdmclk");162MODULE_LICENSE("GPL");163