diff options
Diffstat (limited to 'kernel/drivers/spi/spi-coldfire-qspi.c')
| -rw-r--r-- | kernel/drivers/spi/spi-coldfire-qspi.c | 529 |
1 files changed, 529 insertions, 0 deletions
diff --git a/kernel/drivers/spi/spi-coldfire-qspi.c b/kernel/drivers/spi/spi-coldfire-qspi.c new file mode 100644 index 000000000..688956ff5 --- /dev/null +++ b/kernel/drivers/spi/spi-coldfire-qspi.c @@ -0,0 +1,529 @@ +/* + * Freescale/Motorola Coldfire Queued SPI driver + * + * Copyright 2010 Steven King <sfking@fdwdc.com> + * + * 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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. +*/ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/interrupt.h> +#include <linux/errno.h> +#include <linux/platform_device.h> +#include <linux/sched.h> +#include <linux/delay.h> +#include <linux/io.h> +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/spi/spi.h> +#include <linux/pm_runtime.h> + +#include <asm/coldfire.h> +#include <asm/mcfsim.h> +#include <asm/mcfqspi.h> + +#define DRIVER_NAME "mcfqspi" + +#define MCFQSPI_BUSCLK (MCF_BUSCLK / 2) + +#define MCFQSPI_QMR 0x00 +#define MCFQSPI_QMR_MSTR 0x8000 +#define MCFQSPI_QMR_CPOL 0x0200 +#define MCFQSPI_QMR_CPHA 0x0100 +#define MCFQSPI_QDLYR 0x04 +#define MCFQSPI_QDLYR_SPE 0x8000 +#define MCFQSPI_QWR 0x08 +#define MCFQSPI_QWR_HALT 0x8000 +#define MCFQSPI_QWR_WREN 0x4000 +#define MCFQSPI_QWR_CSIV 0x1000 +#define MCFQSPI_QIR 0x0C +#define MCFQSPI_QIR_WCEFB 0x8000 +#define MCFQSPI_QIR_ABRTB 0x4000 +#define MCFQSPI_QIR_ABRTL 0x1000 +#define MCFQSPI_QIR_WCEFE 0x0800 +#define MCFQSPI_QIR_ABRTE 0x0400 +#define MCFQSPI_QIR_SPIFE 0x0100 +#define MCFQSPI_QIR_WCEF 0x0008 +#define MCFQSPI_QIR_ABRT 0x0004 +#define MCFQSPI_QIR_SPIF 0x0001 +#define MCFQSPI_QAR 0x010 +#define MCFQSPI_QAR_TXBUF 0x00 +#define MCFQSPI_QAR_RXBUF 0x10 +#define MCFQSPI_QAR_CMDBUF 0x20 +#define MCFQSPI_QDR 0x014 +#define MCFQSPI_QCR 0x014 +#define MCFQSPI_QCR_CONT 0x8000 +#define MCFQSPI_QCR_BITSE 0x4000 +#define MCFQSPI_QCR_DT 0x2000 + +struct mcfqspi { + void __iomem *iobase; + int irq; + struct clk *clk; + struct mcfqspi_cs_control *cs_control; + + wait_queue_head_t waitq; +}; + +static void mcfqspi_wr_qmr(struct mcfqspi *mcfqspi, u16 val) +{ + writew(val, mcfqspi->iobase + MCFQSPI_QMR); +} + +static void mcfqspi_wr_qdlyr(struct mcfqspi *mcfqspi, u16 val) +{ + writew(val, mcfqspi->iobase + MCFQSPI_QDLYR); +} + +static u16 mcfqspi_rd_qdlyr(struct mcfqspi *mcfqspi) +{ + return readw(mcfqspi->iobase + MCFQSPI_QDLYR); +} + +static void mcfqspi_wr_qwr(struct mcfqspi *mcfqspi, u16 val) +{ + writew(val, mcfqspi->iobase + MCFQSPI_QWR); +} + +static void mcfqspi_wr_qir(struct mcfqspi *mcfqspi, u16 val) +{ + writew(val, mcfqspi->iobase + MCFQSPI_QIR); +} + +static void mcfqspi_wr_qar(struct mcfqspi *mcfqspi, u16 val) +{ + writew(val, mcfqspi->iobase + MCFQSPI_QAR); +} + +static void mcfqspi_wr_qdr(struct mcfqspi *mcfqspi, u16 val) +{ + writew(val, mcfqspi->iobase + MCFQSPI_QDR); +} + +static u16 mcfqspi_rd_qdr(struct mcfqspi *mcfqspi) +{ + return readw(mcfqspi->iobase + MCFQSPI_QDR); +} + +static void mcfqspi_cs_select(struct mcfqspi *mcfqspi, u8 chip_select, + bool cs_high) +{ + mcfqspi->cs_control->select(mcfqspi->cs_control, chip_select, cs_high); +} + +static void mcfqspi_cs_deselect(struct mcfqspi *mcfqspi, u8 chip_select, + bool cs_high) +{ + mcfqspi->cs_control->deselect(mcfqspi->cs_control, chip_select, cs_high); +} + +static int mcfqspi_cs_setup(struct mcfqspi *mcfqspi) +{ + return (mcfqspi->cs_control->setup) ? + mcfqspi->cs_control->setup(mcfqspi->cs_control) : 0; +} + +static void mcfqspi_cs_teardown(struct mcfqspi *mcfqspi) +{ + if (mcfqspi->cs_control->teardown) + mcfqspi->cs_control->teardown(mcfqspi->cs_control); +} + +static u8 mcfqspi_qmr_baud(u32 speed_hz) +{ + return clamp((MCFQSPI_BUSCLK + speed_hz - 1) / speed_hz, 2u, 255u); +} + +static bool mcfqspi_qdlyr_spe(struct mcfqspi *mcfqspi) +{ + return mcfqspi_rd_qdlyr(mcfqspi) & MCFQSPI_QDLYR_SPE; +} + +static irqreturn_t mcfqspi_irq_handler(int this_irq, void *dev_id) +{ + struct mcfqspi *mcfqspi = dev_id; + + /* clear interrupt */ + mcfqspi_wr_qir(mcfqspi, MCFQSPI_QIR_SPIFE | MCFQSPI_QIR_SPIF); + wake_up(&mcfqspi->waitq); + + return IRQ_HANDLED; +} + +static void mcfqspi_transfer_msg8(struct mcfqspi *mcfqspi, unsigned count, + const u8 *txbuf, u8 *rxbuf) +{ + unsigned i, n, offset = 0; + + n = min(count, 16u); + + mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_CMDBUF); + for (i = 0; i < n; ++i) + mcfqspi_wr_qdr(mcfqspi, MCFQSPI_QCR_BITSE); + + mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_TXBUF); + if (txbuf) + for (i = 0; i < n; ++i) + mcfqspi_wr_qdr(mcfqspi, *txbuf++); + else + for (i = 0; i < count; ++i) + mcfqspi_wr_qdr(mcfqspi, 0); + + count -= n; + if (count) { + u16 qwr = 0xf08; + mcfqspi_wr_qwr(mcfqspi, 0x700); + mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE); + + do { + wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi)); + mcfqspi_wr_qwr(mcfqspi, qwr); + mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE); + if (rxbuf) { + mcfqspi_wr_qar(mcfqspi, + MCFQSPI_QAR_RXBUF + offset); + for (i = 0; i < 8; ++i) + *rxbuf++ = mcfqspi_rd_qdr(mcfqspi); + } + n = min(count, 8u); + if (txbuf) { + mcfqspi_wr_qar(mcfqspi, + MCFQSPI_QAR_TXBUF + offset); + for (i = 0; i < n; ++i) + mcfqspi_wr_qdr(mcfqspi, *txbuf++); + } + qwr = (offset ? 0x808 : 0) + ((n - 1) << 8); + offset ^= 8; + count -= n; + } while (count); + wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi)); + mcfqspi_wr_qwr(mcfqspi, qwr); + mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE); + if (rxbuf) { + mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset); + for (i = 0; i < 8; ++i) + *rxbuf++ = mcfqspi_rd_qdr(mcfqspi); + offset ^= 8; + } + } else { + mcfqspi_wr_qwr(mcfqspi, (n - 1) << 8); + mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE); + } + wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi)); + if (rxbuf) { + mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset); + for (i = 0; i < n; ++i) + *rxbuf++ = mcfqspi_rd_qdr(mcfqspi); + } +} + +static void mcfqspi_transfer_msg16(struct mcfqspi *mcfqspi, unsigned count, + const u16 *txbuf, u16 *rxbuf) +{ + unsigned i, n, offset = 0; + + n = min(count, 16u); + + mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_CMDBUF); + for (i = 0; i < n; ++i) + mcfqspi_wr_qdr(mcfqspi, MCFQSPI_QCR_BITSE); + + mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_TXBUF); + if (txbuf) + for (i = 0; i < n; ++i) + mcfqspi_wr_qdr(mcfqspi, *txbuf++); + else + for (i = 0; i < count; ++i) + mcfqspi_wr_qdr(mcfqspi, 0); + + count -= n; + if (count) { + u16 qwr = 0xf08; + mcfqspi_wr_qwr(mcfqspi, 0x700); + mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE); + + do { + wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi)); + mcfqspi_wr_qwr(mcfqspi, qwr); + mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE); + if (rxbuf) { + mcfqspi_wr_qar(mcfqspi, + MCFQSPI_QAR_RXBUF + offset); + for (i = 0; i < 8; ++i) + *rxbuf++ = mcfqspi_rd_qdr(mcfqspi); + } + n = min(count, 8u); + if (txbuf) { + mcfqspi_wr_qar(mcfqspi, + MCFQSPI_QAR_TXBUF + offset); + for (i = 0; i < n; ++i) + mcfqspi_wr_qdr(mcfqspi, *txbuf++); + } + qwr = (offset ? 0x808 : 0x000) + ((n - 1) << 8); + offset ^= 8; + count -= n; + } while (count); + wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi)); + mcfqspi_wr_qwr(mcfqspi, qwr); + mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE); + if (rxbuf) { + mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset); + for (i = 0; i < 8; ++i) + *rxbuf++ = mcfqspi_rd_qdr(mcfqspi); + offset ^= 8; + } + } else { + mcfqspi_wr_qwr(mcfqspi, (n - 1) << 8); + mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE); + } + wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi)); + if (rxbuf) { + mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset); + for (i = 0; i < n; ++i) + *rxbuf++ = mcfqspi_rd_qdr(mcfqspi); + } +} + +static void mcfqspi_set_cs(struct spi_device *spi, bool enable) +{ + struct mcfqspi *mcfqspi = spi_master_get_devdata(spi->master); + bool cs_high = spi->mode & SPI_CS_HIGH; + + if (enable) + mcfqspi_cs_select(mcfqspi, spi->chip_select, cs_high); + else + mcfqspi_cs_deselect(mcfqspi, spi->chip_select, cs_high); +} + +static int mcfqspi_transfer_one(struct spi_master *master, + struct spi_device *spi, + struct spi_transfer *t) +{ + struct mcfqspi *mcfqspi = spi_master_get_devdata(master); + u16 qmr = MCFQSPI_QMR_MSTR; + + qmr |= t->bits_per_word << 10; + if (spi->mode & SPI_CPHA) + qmr |= MCFQSPI_QMR_CPHA; + if (spi->mode & SPI_CPOL) + qmr |= MCFQSPI_QMR_CPOL; + qmr |= mcfqspi_qmr_baud(t->speed_hz); + mcfqspi_wr_qmr(mcfqspi, qmr); + + mcfqspi_wr_qir(mcfqspi, MCFQSPI_QIR_SPIFE); + if (t->bits_per_word == 8) + mcfqspi_transfer_msg8(mcfqspi, t->len, t->tx_buf, t->rx_buf); + else + mcfqspi_transfer_msg16(mcfqspi, t->len / 2, t->tx_buf, + t->rx_buf); + mcfqspi_wr_qir(mcfqspi, 0); + + return 0; +} + +static int mcfqspi_setup(struct spi_device *spi) +{ + mcfqspi_cs_deselect(spi_master_get_devdata(spi->master), + spi->chip_select, spi->mode & SPI_CS_HIGH); + + dev_dbg(&spi->dev, + "bits per word %d, chip select %d, speed %d KHz\n", + spi->bits_per_word, spi->chip_select, + (MCFQSPI_BUSCLK / mcfqspi_qmr_baud(spi->max_speed_hz)) + / 1000); + + return 0; +} + +static int mcfqspi_probe(struct platform_device *pdev) +{ + struct spi_master *master; + struct mcfqspi *mcfqspi; + struct resource *res; + struct mcfqspi_platform_data *pdata; + int status; + + pdata = dev_get_platdata(&pdev->dev); + if (!pdata) { + dev_dbg(&pdev->dev, "platform data is missing\n"); + return -ENOENT; + } + + if (!pdata->cs_control) { + dev_dbg(&pdev->dev, "pdata->cs_control is NULL\n"); + return -EINVAL; + } + + master = spi_alloc_master(&pdev->dev, sizeof(*mcfqspi)); + if (master == NULL) { + dev_dbg(&pdev->dev, "spi_alloc_master failed\n"); + return -ENOMEM; + } + + mcfqspi = spi_master_get_devdata(master); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + mcfqspi->iobase = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(mcfqspi->iobase)) { + status = PTR_ERR(mcfqspi->iobase); + goto fail0; + } + + mcfqspi->irq = platform_get_irq(pdev, 0); + if (mcfqspi->irq < 0) { + dev_dbg(&pdev->dev, "platform_get_irq failed\n"); + status = -ENXIO; + goto fail0; + } + + status = devm_request_irq(&pdev->dev, mcfqspi->irq, mcfqspi_irq_handler, + 0, pdev->name, mcfqspi); + if (status) { + dev_dbg(&pdev->dev, "request_irq failed\n"); + goto fail0; + } + + mcfqspi->clk = devm_clk_get(&pdev->dev, "qspi_clk"); + if (IS_ERR(mcfqspi->clk)) { + dev_dbg(&pdev->dev, "clk_get failed\n"); + status = PTR_ERR(mcfqspi->clk); + goto fail0; + } + clk_enable(mcfqspi->clk); + + master->bus_num = pdata->bus_num; + master->num_chipselect = pdata->num_chipselect; + + mcfqspi->cs_control = pdata->cs_control; + status = mcfqspi_cs_setup(mcfqspi); + if (status) { + dev_dbg(&pdev->dev, "error initializing cs_control\n"); + goto fail1; + } + + init_waitqueue_head(&mcfqspi->waitq); + + master->mode_bits = SPI_CS_HIGH | SPI_CPOL | SPI_CPHA; + master->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 16); + master->setup = mcfqspi_setup; + master->set_cs = mcfqspi_set_cs; + master->transfer_one = mcfqspi_transfer_one; + master->auto_runtime_pm = true; + + platform_set_drvdata(pdev, master); + + status = devm_spi_register_master(&pdev->dev, master); + if (status) { + dev_dbg(&pdev->dev, "spi_register_master failed\n"); + goto fail2; + } + pm_runtime_enable(&pdev->dev); + + dev_info(&pdev->dev, "Coldfire QSPI bus driver\n"); + + return 0; + +fail2: + mcfqspi_cs_teardown(mcfqspi); +fail1: + clk_disable(mcfqspi->clk); +fail0: + spi_master_put(master); + + dev_dbg(&pdev->dev, "Coldfire QSPI probe failed\n"); + + return status; +} + +static int mcfqspi_remove(struct platform_device *pdev) +{ + struct spi_master *master = platform_get_drvdata(pdev); + struct mcfqspi *mcfqspi = spi_master_get_devdata(master); + + pm_runtime_disable(&pdev->dev); + /* disable the hardware (set the baud rate to 0) */ + mcfqspi_wr_qmr(mcfqspi, MCFQSPI_QMR_MSTR); + + mcfqspi_cs_teardown(mcfqspi); + clk_disable(mcfqspi->clk); + + return 0; +} + +#ifdef CONFIG_PM_SLEEP +static int mcfqspi_suspend(struct device *dev) +{ + struct spi_master *master = dev_get_drvdata(dev); + struct mcfqspi *mcfqspi = spi_master_get_devdata(master); + int ret; + + ret = spi_master_suspend(master); + if (ret) + return ret; + + clk_disable(mcfqspi->clk); + + return 0; +} + +static int mcfqspi_resume(struct device *dev) +{ + struct spi_master *master = dev_get_drvdata(dev); + struct mcfqspi *mcfqspi = spi_master_get_devdata(master); + + clk_enable(mcfqspi->clk); + + return spi_master_resume(master); +} +#endif + +#ifdef CONFIG_PM +static int mcfqspi_runtime_suspend(struct device *dev) +{ + struct spi_master *master = dev_get_drvdata(dev); + struct mcfqspi *mcfqspi = spi_master_get_devdata(master); + + clk_disable(mcfqspi->clk); + + return 0; +} + +static int mcfqspi_runtime_resume(struct device *dev) +{ + struct spi_master *master = dev_get_drvdata(dev); + struct mcfqspi *mcfqspi = spi_master_get_devdata(master); + + clk_enable(mcfqspi->clk); + + return 0; +} +#endif + +static const struct dev_pm_ops mcfqspi_pm = { + SET_SYSTEM_SLEEP_PM_OPS(mcfqspi_suspend, mcfqspi_resume) + SET_RUNTIME_PM_OPS(mcfqspi_runtime_suspend, mcfqspi_runtime_resume, + NULL) +}; + +static struct platform_driver mcfqspi_driver = { + .driver.name = DRIVER_NAME, + .driver.owner = THIS_MODULE, + .driver.pm = &mcfqspi_pm, + .probe = mcfqspi_probe, + .remove = mcfqspi_remove, +}; +module_platform_driver(mcfqspi_driver); + +MODULE_AUTHOR("Steven King <sfking@fdwdc.com>"); +MODULE_DESCRIPTION("Coldfire QSPI Controller Driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:" DRIVER_NAME); |