163 lines
3.7 KiB
C
163 lines
3.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* TWL6040 clock module driver for OMAP4 McPDM functional clock
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*
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* Copyright (C) 2012 Texas Instruments Inc.
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* Peter Ujfalusi <peter.ujfalusi@ti.com>
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*/
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/platform_device.h>
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#include <linux/mfd/twl6040.h>
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#include <linux/clk-provider.h>
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struct twl6040_pdmclk {
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struct twl6040 *twl6040;
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struct device *dev;
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struct clk_hw pdmclk_hw;
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int enabled;
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};
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static int twl6040_pdmclk_is_prepared(struct clk_hw *hw)
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{
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struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk,
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pdmclk_hw);
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return pdmclk->enabled;
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}
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static int twl6040_pdmclk_reset_one_clock(struct twl6040_pdmclk *pdmclk,
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unsigned int reg)
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{
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const u8 reset_mask = TWL6040_HPLLRST; /* Same for HPPLL and LPPLL */
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int ret;
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ret = twl6040_set_bits(pdmclk->twl6040, reg, reset_mask);
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if (ret < 0)
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return ret;
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ret = twl6040_clear_bits(pdmclk->twl6040, reg, reset_mask);
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if (ret < 0)
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return ret;
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return 0;
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}
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/*
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* TWL6040A2 Phoenix Audio IC erratum #6: "PDM Clock Generation Issue At
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* Cold Temperature". This affects cold boot and deeper idle states it
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* seems. The workaround consists of resetting HPPLL and LPPLL.
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*/
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static int twl6040_pdmclk_quirk_reset_clocks(struct twl6040_pdmclk *pdmclk)
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{
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int ret;
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ret = twl6040_pdmclk_reset_one_clock(pdmclk, TWL6040_REG_HPPLLCTL);
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if (ret)
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return ret;
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ret = twl6040_pdmclk_reset_one_clock(pdmclk, TWL6040_REG_LPPLLCTL);
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if (ret)
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return ret;
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return 0;
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}
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static int twl6040_pdmclk_prepare(struct clk_hw *hw)
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{
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struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk,
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pdmclk_hw);
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int ret;
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ret = twl6040_power(pdmclk->twl6040, 1);
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if (ret)
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return ret;
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ret = twl6040_pdmclk_quirk_reset_clocks(pdmclk);
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if (ret)
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goto out_err;
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pdmclk->enabled = 1;
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return 0;
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out_err:
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dev_err(pdmclk->dev, "%s: error %i\n", __func__, ret);
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twl6040_power(pdmclk->twl6040, 0);
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return ret;
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}
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static void twl6040_pdmclk_unprepare(struct clk_hw *hw)
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{
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struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk,
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pdmclk_hw);
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int ret;
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ret = twl6040_power(pdmclk->twl6040, 0);
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if (!ret)
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pdmclk->enabled = 0;
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}
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static unsigned long twl6040_pdmclk_recalc_rate(struct clk_hw *hw,
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unsigned long parent_rate)
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{
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struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk,
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pdmclk_hw);
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return twl6040_get_sysclk(pdmclk->twl6040);
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}
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static const struct clk_ops twl6040_pdmclk_ops = {
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.is_prepared = twl6040_pdmclk_is_prepared,
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.prepare = twl6040_pdmclk_prepare,
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.unprepare = twl6040_pdmclk_unprepare,
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.recalc_rate = twl6040_pdmclk_recalc_rate,
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};
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static const struct clk_init_data twl6040_pdmclk_init = {
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.name = "pdmclk",
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.ops = &twl6040_pdmclk_ops,
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.flags = CLK_GET_RATE_NOCACHE,
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};
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static int twl6040_pdmclk_probe(struct platform_device *pdev)
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{
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struct twl6040 *twl6040 = dev_get_drvdata(pdev->dev.parent);
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struct twl6040_pdmclk *clkdata;
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int ret;
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clkdata = devm_kzalloc(&pdev->dev, sizeof(*clkdata), GFP_KERNEL);
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if (!clkdata)
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return -ENOMEM;
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clkdata->dev = &pdev->dev;
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clkdata->twl6040 = twl6040;
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clkdata->pdmclk_hw.init = &twl6040_pdmclk_init;
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ret = devm_clk_hw_register(&pdev->dev, &clkdata->pdmclk_hw);
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if (ret)
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return ret;
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platform_set_drvdata(pdev, clkdata);
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return devm_of_clk_add_hw_provider(&pdev->dev, of_clk_hw_simple_get,
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&clkdata->pdmclk_hw);
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}
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static struct platform_driver twl6040_pdmclk_driver = {
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.driver = {
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.name = "twl6040-pdmclk",
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},
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.probe = twl6040_pdmclk_probe,
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};
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module_platform_driver(twl6040_pdmclk_driver);
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MODULE_DESCRIPTION("TWL6040 clock driver for McPDM functional clock");
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MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
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MODULE_ALIAS("platform:twl6040-pdmclk");
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MODULE_LICENSE("GPL");
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