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054320b255
This converts the CLPS711x SPI master driver to use GPIO descriptors for chip select handling. The CLPS711x driver was merely requesting the GPIO and setting the CS line non-asserted so this was a pretty straight-forward conversion. The setup callback goes away. Cc: Alexander Shiyan <shc_work@mail.ru> Cc: Linuxarm <linuxarm@huawei.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Mark Brown <broonie@kernel.org>
179 lines
4.3 KiB
C
179 lines
4.3 KiB
C
/*
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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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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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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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