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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 | // SPDX-License-Identifier: GPL-2.0-only /* * TWL6040 clock module driver for OMAP4 McPDM functional clock * * Copyright (C) 2012 Texas Instruments Inc. * Peter Ujfalusi <peter.ujfalusi@ti.com> */ #include <linux/module.h> #include <linux/slab.h> #include <linux/platform_device.h> #include <linux/mfd/twl6040.h> #include <linux/clk-provider.h> struct twl6040_pdmclk { struct twl6040 *twl6040; struct device *dev; struct clk_hw pdmclk_hw; int enabled; }; static int twl6040_pdmclk_is_prepared(struct clk_hw *hw) { struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk, pdmclk_hw); return pdmclk->enabled; } static int twl6040_pdmclk_reset_one_clock(struct twl6040_pdmclk *pdmclk, unsigned int reg) { const u8 reset_mask = TWL6040_HPLLRST; /* Same for HPPLL and LPPLL */ int ret; ret = twl6040_set_bits(pdmclk->twl6040, reg, reset_mask); if (ret < 0) return ret; ret = twl6040_clear_bits(pdmclk->twl6040, reg, reset_mask); if (ret < 0) return ret; return 0; } /* * TWL6040A2 Phoenix Audio IC erratum #6: "PDM Clock Generation Issue At * Cold Temperature". This affects cold boot and deeper idle states it * seems. The workaround consists of resetting HPPLL and LPPLL. */ static int twl6040_pdmclk_quirk_reset_clocks(struct twl6040_pdmclk *pdmclk) { int ret; ret = twl6040_pdmclk_reset_one_clock(pdmclk, TWL6040_REG_HPPLLCTL); if (ret) return ret; ret = twl6040_pdmclk_reset_one_clock(pdmclk, TWL6040_REG_LPPLLCTL); if (ret) return ret; return 0; } static int twl6040_pdmclk_prepare(struct clk_hw *hw) { struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk, pdmclk_hw); int ret; ret = twl6040_power(pdmclk->twl6040, 1); if (ret) return ret; ret = twl6040_pdmclk_quirk_reset_clocks(pdmclk); if (ret) goto out_err; pdmclk->enabled = 1; return 0; out_err: dev_err(pdmclk->dev, "%s: error %i\n", __func__, ret); twl6040_power(pdmclk->twl6040, 0); return ret; } static void twl6040_pdmclk_unprepare(struct clk_hw *hw) { struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk, pdmclk_hw); int ret; ret = twl6040_power(pdmclk->twl6040, 0); if (!ret) pdmclk->enabled = 0; } static unsigned long twl6040_pdmclk_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) { struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk, pdmclk_hw); return twl6040_get_sysclk(pdmclk->twl6040); } static const struct clk_ops twl6040_pdmclk_ops = { .is_prepared = twl6040_pdmclk_is_prepared, .prepare = twl6040_pdmclk_prepare, .unprepare = twl6040_pdmclk_unprepare, .recalc_rate = twl6040_pdmclk_recalc_rate, }; static const struct clk_init_data twl6040_pdmclk_init = { .name = "pdmclk", .ops = &twl6040_pdmclk_ops, .flags = CLK_GET_RATE_NOCACHE, }; static int twl6040_pdmclk_probe(struct platform_device *pdev) { struct twl6040 *twl6040 = dev_get_drvdata(pdev->dev.parent); struct twl6040_pdmclk *clkdata; int ret; clkdata = devm_kzalloc(&pdev->dev, sizeof(*clkdata), GFP_KERNEL); if (!clkdata) return -ENOMEM; clkdata->dev = &pdev->dev; clkdata->twl6040 = twl6040; clkdata->pdmclk_hw.init = &twl6040_pdmclk_init; ret = devm_clk_hw_register(&pdev->dev, &clkdata->pdmclk_hw); if (ret) return ret; platform_set_drvdata(pdev, clkdata); return devm_of_clk_add_hw_provider(&pdev->dev, of_clk_hw_simple_get, &clkdata->pdmclk_hw); } static struct platform_driver twl6040_pdmclk_driver = { .driver = { .name = "twl6040-pdmclk", }, .probe = twl6040_pdmclk_probe, }; module_platform_driver(twl6040_pdmclk_driver); MODULE_DESCRIPTION("TWL6040 clock driver for McPDM functional clock"); MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>"); MODULE_ALIAS("platform:twl6040-pdmclk"); MODULE_LICENSE("GPL"); |