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795b3ac702
The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is (mostly) ignored and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new() which already returns void. Trivially convert this driver from always returning zero in the remove callback to the void returning variant. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20230303172041.2103336-86-u.kleine-koenig@pengutronix.de Signed-off-by: Mark Brown <broonie@kernel.org>
152 lines
3.7 KiB
C
152 lines
3.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Xtensa xtfpga SPI controller driver
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*
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* Copyright (c) 2014 Cadence Design Systems Inc.
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*/
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#include <linux/delay.h>
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#include <linux/io.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/spi/spi.h>
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#include <linux/spi/spi_bitbang.h>
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#define XTFPGA_SPI_NAME "xtfpga_spi"
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#define XTFPGA_SPI_START 0x0
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#define XTFPGA_SPI_BUSY 0x4
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#define XTFPGA_SPI_DATA 0x8
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#define BUSY_WAIT_US 100
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struct xtfpga_spi {
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struct spi_bitbang bitbang;
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void __iomem *regs;
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u32 data;
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unsigned data_sz;
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};
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static inline void xtfpga_spi_write32(const struct xtfpga_spi *spi,
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unsigned addr, u32 val)
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{
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__raw_writel(val, spi->regs + addr);
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}
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static inline unsigned int xtfpga_spi_read32(const struct xtfpga_spi *spi,
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unsigned addr)
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{
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return __raw_readl(spi->regs + addr);
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}
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static inline void xtfpga_spi_wait_busy(struct xtfpga_spi *xspi)
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{
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unsigned i;
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for (i = 0; xtfpga_spi_read32(xspi, XTFPGA_SPI_BUSY) &&
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i < BUSY_WAIT_US; ++i)
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udelay(1);
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WARN_ON_ONCE(i == BUSY_WAIT_US);
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}
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static u32 xtfpga_spi_txrx_word(struct spi_device *spi, unsigned nsecs,
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u32 v, u8 bits, unsigned flags)
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{
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struct xtfpga_spi *xspi = spi_master_get_devdata(spi->master);
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xspi->data = (xspi->data << bits) | (v & GENMASK(bits - 1, 0));
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xspi->data_sz += bits;
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if (xspi->data_sz >= 16) {
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xtfpga_spi_write32(xspi, XTFPGA_SPI_DATA,
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xspi->data >> (xspi->data_sz - 16));
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xspi->data_sz -= 16;
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xtfpga_spi_write32(xspi, XTFPGA_SPI_START, 1);
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xtfpga_spi_wait_busy(xspi);
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xtfpga_spi_write32(xspi, XTFPGA_SPI_START, 0);
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}
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return 0;
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}
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static void xtfpga_spi_chipselect(struct spi_device *spi, int is_on)
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{
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struct xtfpga_spi *xspi = spi_master_get_devdata(spi->master);
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WARN_ON(xspi->data_sz != 0);
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xspi->data_sz = 0;
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}
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static int xtfpga_spi_probe(struct platform_device *pdev)
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{
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struct xtfpga_spi *xspi;
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int ret;
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struct spi_master *master;
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master = devm_spi_alloc_master(&pdev->dev, sizeof(struct xtfpga_spi));
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if (!master)
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return -ENOMEM;
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master->flags = SPI_MASTER_NO_RX;
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master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 16);
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master->bus_num = pdev->dev.id;
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master->dev.of_node = pdev->dev.of_node;
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xspi = spi_master_get_devdata(master);
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xspi->bitbang.master = master;
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xspi->bitbang.chipselect = xtfpga_spi_chipselect;
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xspi->bitbang.txrx_word[SPI_MODE_0] = xtfpga_spi_txrx_word;
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xspi->regs = devm_platform_ioremap_resource(pdev, 0);
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if (IS_ERR(xspi->regs))
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return PTR_ERR(xspi->regs);
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xtfpga_spi_write32(xspi, XTFPGA_SPI_START, 0);
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usleep_range(1000, 2000);
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if (xtfpga_spi_read32(xspi, XTFPGA_SPI_BUSY)) {
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dev_err(&pdev->dev, "Device stuck in busy state\n");
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return -EBUSY;
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}
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ret = spi_bitbang_start(&xspi->bitbang);
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if (ret < 0) {
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dev_err(&pdev->dev, "spi_bitbang_start failed\n");
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return ret;
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}
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platform_set_drvdata(pdev, master);
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return 0;
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}
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static void xtfpga_spi_remove(struct platform_device *pdev)
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{
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struct spi_master *master = platform_get_drvdata(pdev);
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struct xtfpga_spi *xspi = spi_master_get_devdata(master);
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spi_bitbang_stop(&xspi->bitbang);
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spi_master_put(master);
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}
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MODULE_ALIAS("platform:" XTFPGA_SPI_NAME);
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#ifdef CONFIG_OF
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static const struct of_device_id xtfpga_spi_of_match[] = {
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{ .compatible = "cdns,xtfpga-spi", },
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{}
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};
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MODULE_DEVICE_TABLE(of, xtfpga_spi_of_match);
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#endif
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static struct platform_driver xtfpga_spi_driver = {
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.probe = xtfpga_spi_probe,
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.remove_new = xtfpga_spi_remove,
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.driver = {
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.name = XTFPGA_SPI_NAME,
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.of_match_table = of_match_ptr(xtfpga_spi_of_match),
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},
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};
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module_platform_driver(xtfpga_spi_driver);
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MODULE_AUTHOR("Max Filippov <jcmvbkbc@gmail.com>");
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MODULE_DESCRIPTION("xtensa xtfpga SPI driver");
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MODULE_LICENSE("GPL");
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