From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- drivers/spi/spi-oc-tiny.c | 306 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 306 insertions(+) create mode 100644 drivers/spi/spi-oc-tiny.c (limited to 'drivers/spi/spi-oc-tiny.c') diff --git a/drivers/spi/spi-oc-tiny.c b/drivers/spi/spi-oc-tiny.c new file mode 100644 index 000000000..38c14c4e4 --- /dev/null +++ b/drivers/spi/spi-oc-tiny.c @@ -0,0 +1,306 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * OpenCores tiny SPI master driver + * + * https://opencores.org/project,tiny_spi + * + * Copyright (C) 2011 Thomas Chou + * + * Based on spi_s3c24xx.c, which is: + * Copyright (c) 2006 Ben Dooks + * Copyright (c) 2006 Simtec Electronics + * Ben Dooks + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define DRV_NAME "spi_oc_tiny" + +#define TINY_SPI_RXDATA 0 +#define TINY_SPI_TXDATA 4 +#define TINY_SPI_STATUS 8 +#define TINY_SPI_CONTROL 12 +#define TINY_SPI_BAUD 16 + +#define TINY_SPI_STATUS_TXE 0x1 +#define TINY_SPI_STATUS_TXR 0x2 + +struct tiny_spi { + /* bitbang has to be first */ + struct spi_bitbang bitbang; + struct completion done; + + void __iomem *base; + int irq; + unsigned int freq; + unsigned int baudwidth; + unsigned int baud; + unsigned int speed_hz; + unsigned int mode; + unsigned int len; + unsigned int txc, rxc; + const u8 *txp; + u8 *rxp; +}; + +static inline struct tiny_spi *tiny_spi_to_hw(struct spi_device *sdev) +{ + return spi_master_get_devdata(sdev->master); +} + +static unsigned int tiny_spi_baud(struct spi_device *spi, unsigned int hz) +{ + struct tiny_spi *hw = tiny_spi_to_hw(spi); + + return min(DIV_ROUND_UP(hw->freq, hz * 2), (1U << hw->baudwidth)) - 1; +} + +static int tiny_spi_setup_transfer(struct spi_device *spi, + struct spi_transfer *t) +{ + struct tiny_spi *hw = tiny_spi_to_hw(spi); + unsigned int baud = hw->baud; + + if (t) { + if (t->speed_hz && t->speed_hz != hw->speed_hz) + baud = tiny_spi_baud(spi, t->speed_hz); + } + writel(baud, hw->base + TINY_SPI_BAUD); + writel(hw->mode, hw->base + TINY_SPI_CONTROL); + return 0; +} + +static int tiny_spi_setup(struct spi_device *spi) +{ + struct tiny_spi *hw = tiny_spi_to_hw(spi); + + if (spi->max_speed_hz != hw->speed_hz) { + hw->speed_hz = spi->max_speed_hz; + hw->baud = tiny_spi_baud(spi, hw->speed_hz); + } + hw->mode = spi->mode & SPI_MODE_X_MASK; + return 0; +} + +static inline void tiny_spi_wait_txr(struct tiny_spi *hw) +{ + while (!(readb(hw->base + TINY_SPI_STATUS) & + TINY_SPI_STATUS_TXR)) + cpu_relax(); +} + +static inline void tiny_spi_wait_txe(struct tiny_spi *hw) +{ + while (!(readb(hw->base + TINY_SPI_STATUS) & + TINY_SPI_STATUS_TXE)) + cpu_relax(); +} + +static int tiny_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t) +{ + struct tiny_spi *hw = tiny_spi_to_hw(spi); + const u8 *txp = t->tx_buf; + u8 *rxp = t->rx_buf; + unsigned int i; + + if (hw->irq >= 0) { + /* use interrupt driven data transfer */ + hw->len = t->len; + hw->txp = t->tx_buf; + hw->rxp = t->rx_buf; + hw->txc = 0; + hw->rxc = 0; + + /* send the first byte */ + if (t->len > 1) { + writeb(hw->txp ? *hw->txp++ : 0, + hw->base + TINY_SPI_TXDATA); + hw->txc++; + writeb(hw->txp ? *hw->txp++ : 0, + hw->base + TINY_SPI_TXDATA); + hw->txc++; + writeb(TINY_SPI_STATUS_TXR, hw->base + TINY_SPI_STATUS); + } else { + writeb(hw->txp ? *hw->txp++ : 0, + hw->base + TINY_SPI_TXDATA); + hw->txc++; + writeb(TINY_SPI_STATUS_TXE, hw->base + TINY_SPI_STATUS); + } + + wait_for_completion(&hw->done); + } else { + /* we need to tighten the transfer loop */ + writeb(txp ? *txp++ : 0, hw->base + TINY_SPI_TXDATA); + for (i = 1; i < t->len; i++) { + writeb(txp ? *txp++ : 0, hw->base + TINY_SPI_TXDATA); + + if (rxp || (i != t->len - 1)) + tiny_spi_wait_txr(hw); + if (rxp) + *rxp++ = readb(hw->base + TINY_SPI_TXDATA); + } + tiny_spi_wait_txe(hw); + if (rxp) + *rxp++ = readb(hw->base + TINY_SPI_RXDATA); + } + + return t->len; +} + +static irqreturn_t tiny_spi_irq(int irq, void *dev) +{ + struct tiny_spi *hw = dev; + + writeb(0, hw->base + TINY_SPI_STATUS); + if (hw->rxc + 1 == hw->len) { + if (hw->rxp) + *hw->rxp++ = readb(hw->base + TINY_SPI_RXDATA); + hw->rxc++; + complete(&hw->done); + } else { + if (hw->rxp) + *hw->rxp++ = readb(hw->base + TINY_SPI_TXDATA); + hw->rxc++; + if (hw->txc < hw->len) { + writeb(hw->txp ? *hw->txp++ : 0, + hw->base + TINY_SPI_TXDATA); + hw->txc++; + writeb(TINY_SPI_STATUS_TXR, + hw->base + TINY_SPI_STATUS); + } else { + writeb(TINY_SPI_STATUS_TXE, + hw->base + TINY_SPI_STATUS); + } + } + return IRQ_HANDLED; +} + +#ifdef CONFIG_OF +#include + +static int tiny_spi_of_probe(struct platform_device *pdev) +{ + struct tiny_spi *hw = platform_get_drvdata(pdev); + struct device_node *np = pdev->dev.of_node; + u32 val; + + if (!np) + return 0; + hw->bitbang.master->dev.of_node = pdev->dev.of_node; + if (!of_property_read_u32(np, "clock-frequency", &val)) + hw->freq = val; + if (!of_property_read_u32(np, "baud-width", &val)) + hw->baudwidth = val; + return 0; +} +#else /* !CONFIG_OF */ +static int tiny_spi_of_probe(struct platform_device *pdev) +{ + return 0; +} +#endif /* CONFIG_OF */ + +static int tiny_spi_probe(struct platform_device *pdev) +{ + struct tiny_spi_platform_data *platp = dev_get_platdata(&pdev->dev); + struct tiny_spi *hw; + struct spi_master *master; + int err = -ENODEV; + + master = spi_alloc_master(&pdev->dev, sizeof(struct tiny_spi)); + if (!master) + return err; + + /* setup the master state. */ + master->bus_num = pdev->id; + master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH; + master->setup = tiny_spi_setup; + master->use_gpio_descriptors = true; + + hw = spi_master_get_devdata(master); + platform_set_drvdata(pdev, hw); + + /* setup the state for the bitbang driver */ + hw->bitbang.master = master; + hw->bitbang.setup_transfer = tiny_spi_setup_transfer; + hw->bitbang.txrx_bufs = tiny_spi_txrx_bufs; + + /* find and map our resources */ + hw->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(hw->base)) { + err = PTR_ERR(hw->base); + goto exit; + } + /* irq is optional */ + hw->irq = platform_get_irq(pdev, 0); + if (hw->irq >= 0) { + init_completion(&hw->done); + err = devm_request_irq(&pdev->dev, hw->irq, tiny_spi_irq, 0, + pdev->name, hw); + if (err) + goto exit; + } + /* find platform data */ + if (platp) { + hw->freq = platp->freq; + hw->baudwidth = platp->baudwidth; + } else { + err = tiny_spi_of_probe(pdev); + if (err) + goto exit; + } + + /* register our spi controller */ + err = spi_bitbang_start(&hw->bitbang); + if (err) + goto exit; + dev_info(&pdev->dev, "base %p, irq %d\n", hw->base, hw->irq); + + return 0; + +exit: + spi_master_put(master); + return err; +} + +static int tiny_spi_remove(struct platform_device *pdev) +{ + struct tiny_spi *hw = platform_get_drvdata(pdev); + struct spi_master *master = hw->bitbang.master; + + spi_bitbang_stop(&hw->bitbang); + spi_master_put(master); + return 0; +} + +#ifdef CONFIG_OF +static const struct of_device_id tiny_spi_match[] = { + { .compatible = "opencores,tiny-spi-rtlsvn2", }, + {}, +}; +MODULE_DEVICE_TABLE(of, tiny_spi_match); +#endif /* CONFIG_OF */ + +static struct platform_driver tiny_spi_driver = { + .probe = tiny_spi_probe, + .remove = tiny_spi_remove, + .driver = { + .name = DRV_NAME, + .pm = NULL, + .of_match_table = of_match_ptr(tiny_spi_match), + }, +}; +module_platform_driver(tiny_spi_driver); + +MODULE_DESCRIPTION("OpenCores tiny SPI driver"); +MODULE_AUTHOR("Thomas Chou "); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:" DRV_NAME); -- cgit v1.2.3