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6979e56cec
TI's J721e SoC has a Cadence UFS IP with a TI specific wrapper. This is a minimal driver to configure the wrapper. It releases the UFS slave device out of reset and sets up registers to indicate PHY reference clock input frequency before probing child Cadence UFS driver. Link: https://lore.kernel.org/r/20191108164857.11466-3-vigneshr@ti.com Reviewed-by: Avri Altman <avri.altman@wdc.com> Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com> Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
90 lines
2 KiB
C
90 lines
2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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//
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// Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com/
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//
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#include <linux/clk.h>
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#include <linux/io.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/of_platform.h>
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#include <linux/platform_device.h>
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#include <linux/pm_runtime.h>
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#define TI_UFS_SS_CTRL 0x4
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#define TI_UFS_SS_RST_N_PCS BIT(0)
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#define TI_UFS_SS_CLK_26MHZ BIT(4)
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static int ti_j721e_ufs_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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unsigned long clk_rate;
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void __iomem *regbase;
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struct clk *clk;
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u32 reg = 0;
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int ret;
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regbase = devm_platform_ioremap_resource(pdev, 0);
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if (IS_ERR(regbase))
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return PTR_ERR(regbase);
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pm_runtime_enable(dev);
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ret = pm_runtime_get_sync(dev);
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if (ret < 0) {
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pm_runtime_put_noidle(dev);
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return ret;
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}
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/* Select MPHY refclk frequency */
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clk = devm_clk_get(dev, NULL);
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if (IS_ERR(clk)) {
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dev_err(dev, "Cannot claim MPHY clock.\n");
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return PTR_ERR(clk);
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}
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clk_rate = clk_get_rate(clk);
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if (clk_rate == 26000000)
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reg |= TI_UFS_SS_CLK_26MHZ;
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devm_clk_put(dev, clk);
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/* Take UFS slave device out of reset */
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reg |= TI_UFS_SS_RST_N_PCS;
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writel(reg, regbase + TI_UFS_SS_CTRL);
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ret = of_platform_populate(pdev->dev.of_node, NULL, NULL,
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dev);
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if (ret) {
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dev_err(dev, "failed to populate child nodes %d\n", ret);
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pm_runtime_put_sync(dev);
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}
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return ret;
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}
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static int ti_j721e_ufs_remove(struct platform_device *pdev)
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{
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of_platform_depopulate(&pdev->dev);
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pm_runtime_put_sync(&pdev->dev);
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return 0;
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}
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static const struct of_device_id ti_j721e_ufs_of_match[] = {
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{
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.compatible = "ti,j721e-ufs",
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},
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{ },
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};
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static struct platform_driver ti_j721e_ufs_driver = {
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.probe = ti_j721e_ufs_probe,
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.remove = ti_j721e_ufs_remove,
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.driver = {
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.name = "ti-j721e-ufs",
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.of_match_table = ti_j721e_ufs_of_match,
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},
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};
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module_platform_driver(ti_j721e_ufs_driver);
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MODULE_AUTHOR("Vignesh Raghavendra <vigneshr@ti.com>");
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MODULE_DESCRIPTION("TI UFS host controller glue driver");
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MODULE_LICENSE("GPL v2");
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