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![Thomas Gleixner](/assets/img/avatar_default.png)
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
174 lines
4.1 KiB
C
174 lines
4.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* CLPS711X SPI bus driver
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*
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* Copyright (C) 2012-2016 Alexander Shiyan <shc_work@mail.ru>
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*/
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#include <linux/io.h>
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#include <linux/clk.h>
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#include <linux/gpio/consumer.h>
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#include <linux/module.h>
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#include <linux/interrupt.h>
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#include <linux/platform_device.h>
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#include <linux/regmap.h>
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#include <linux/mfd/syscon.h>
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#include <linux/mfd/syscon/clps711x.h>
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#include <linux/spi/spi.h>
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#define DRIVER_NAME "clps711x-spi"
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#define SYNCIO_FRMLEN(x) ((x) << 8)
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#define SYNCIO_TXFRMEN (1 << 14)
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struct spi_clps711x_data {
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void __iomem *syncio;
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struct regmap *syscon;
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struct clk *spi_clk;
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u8 *tx_buf;
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u8 *rx_buf;
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unsigned int bpw;
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int len;
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};
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static int spi_clps711x_prepare_message(struct spi_master *master,
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struct spi_message *msg)
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{
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struct spi_clps711x_data *hw = spi_master_get_devdata(master);
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struct spi_device *spi = msg->spi;
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/* Setup mode for transfer */
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return regmap_update_bits(hw->syscon, SYSCON_OFFSET, SYSCON3_ADCCKNSEN,
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(spi->mode & SPI_CPHA) ?
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SYSCON3_ADCCKNSEN : 0);
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}
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static int spi_clps711x_transfer_one(struct spi_master *master,
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struct spi_device *spi,
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struct spi_transfer *xfer)
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{
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struct spi_clps711x_data *hw = spi_master_get_devdata(master);
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u8 data;
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clk_set_rate(hw->spi_clk, xfer->speed_hz ? : spi->max_speed_hz);
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hw->len = xfer->len;
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hw->bpw = xfer->bits_per_word;
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hw->tx_buf = (u8 *)xfer->tx_buf;
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hw->rx_buf = (u8 *)xfer->rx_buf;
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/* Initiate transfer */
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data = hw->tx_buf ? *hw->tx_buf++ : 0;
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writel(data | SYNCIO_FRMLEN(hw->bpw) | SYNCIO_TXFRMEN, hw->syncio);
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return 1;
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}
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static irqreturn_t spi_clps711x_isr(int irq, void *dev_id)
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{
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struct spi_master *master = dev_id;
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struct spi_clps711x_data *hw = spi_master_get_devdata(master);
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u8 data;
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/* Handle RX */
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data = readb(hw->syncio);
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if (hw->rx_buf)
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*hw->rx_buf++ = data;
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/* Handle TX */
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if (--hw->len > 0) {
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data = hw->tx_buf ? *hw->tx_buf++ : 0;
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writel(data | SYNCIO_FRMLEN(hw->bpw) | SYNCIO_TXFRMEN,
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hw->syncio);
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} else
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spi_finalize_current_transfer(master);
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return IRQ_HANDLED;
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}
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static int spi_clps711x_probe(struct platform_device *pdev)
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{
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struct spi_clps711x_data *hw;
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struct spi_master *master;
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struct resource *res;
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int irq, ret;
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irq = platform_get_irq(pdev, 0);
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if (irq < 0)
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return irq;
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master = spi_alloc_master(&pdev->dev, sizeof(*hw));
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if (!master)
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return -ENOMEM;
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master->use_gpio_descriptors = true;
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master->bus_num = -1;
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master->mode_bits = SPI_CPHA | SPI_CS_HIGH;
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master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 8);
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master->dev.of_node = pdev->dev.of_node;
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master->prepare_message = spi_clps711x_prepare_message;
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master->transfer_one = spi_clps711x_transfer_one;
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hw = spi_master_get_devdata(master);
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hw->spi_clk = devm_clk_get(&pdev->dev, NULL);
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if (IS_ERR(hw->spi_clk)) {
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ret = PTR_ERR(hw->spi_clk);
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goto err_out;
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}
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hw->syscon =
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syscon_regmap_lookup_by_compatible("cirrus,ep7209-syscon3");
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if (IS_ERR(hw->syscon)) {
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ret = PTR_ERR(hw->syscon);
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goto err_out;
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}
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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hw->syncio = devm_ioremap_resource(&pdev->dev, res);
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if (IS_ERR(hw->syncio)) {
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ret = PTR_ERR(hw->syncio);
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goto err_out;
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}
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/* Disable extended mode due hardware problems */
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regmap_update_bits(hw->syscon, SYSCON_OFFSET, SYSCON3_ADCCON, 0);
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/* Clear possible pending interrupt */
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readl(hw->syncio);
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ret = devm_request_irq(&pdev->dev, irq, spi_clps711x_isr, 0,
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dev_name(&pdev->dev), master);
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if (ret)
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goto err_out;
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ret = devm_spi_register_master(&pdev->dev, master);
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if (!ret)
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return 0;
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err_out:
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spi_master_put(master);
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return ret;
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}
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static const struct of_device_id clps711x_spi_dt_ids[] = {
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{ .compatible = "cirrus,ep7209-spi", },
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{ }
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};
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MODULE_DEVICE_TABLE(of, clps711x_spi_dt_ids);
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static struct platform_driver clps711x_spi_driver = {
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.driver = {
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.name = DRIVER_NAME,
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.of_match_table = clps711x_spi_dt_ids,
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},
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.probe = spi_clps711x_probe,
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};
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module_platform_driver(clps711x_spi_driver);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
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MODULE_DESCRIPTION("CLPS711X SPI bus driver");
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MODULE_ALIAS("platform:" DRIVER_NAME);
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