From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/drivers/spi/spi-ath79.c | 317 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 317 insertions(+) create mode 100644 kernel/drivers/spi/spi-ath79.c (limited to 'kernel/drivers/spi/spi-ath79.c') diff --git a/kernel/drivers/spi/spi-ath79.c b/kernel/drivers/spi/spi-ath79.c new file mode 100644 index 000000000..b02eb4ac0 --- /dev/null +++ b/kernel/drivers/spi/spi-ath79.c @@ -0,0 +1,317 @@ +/* + * SPI controller driver for the Atheros AR71XX/AR724X/AR913X SoCs + * + * Copyright (C) 2009-2011 Gabor Juhos + * + * This driver has been based on the spi-gpio.c: + * Copyright (C) 2006,2008 David Brownell + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#define DRV_NAME "ath79-spi" + +#define ATH79_SPI_RRW_DELAY_FACTOR 12000 +#define MHZ (1000 * 1000) + +struct ath79_spi { + struct spi_bitbang bitbang; + u32 ioc_base; + u32 reg_ctrl; + void __iomem *base; + struct clk *clk; + unsigned rrw_delay; +}; + +static inline u32 ath79_spi_rr(struct ath79_spi *sp, unsigned reg) +{ + return ioread32(sp->base + reg); +} + +static inline void ath79_spi_wr(struct ath79_spi *sp, unsigned reg, u32 val) +{ + iowrite32(val, sp->base + reg); +} + +static inline struct ath79_spi *ath79_spidev_to_sp(struct spi_device *spi) +{ + return spi_master_get_devdata(spi->master); +} + +static inline void ath79_spi_delay(struct ath79_spi *sp, unsigned nsecs) +{ + if (nsecs > sp->rrw_delay) + ndelay(nsecs - sp->rrw_delay); +} + +static void ath79_spi_chipselect(struct spi_device *spi, int is_active) +{ + struct ath79_spi *sp = ath79_spidev_to_sp(spi); + int cs_high = (spi->mode & SPI_CS_HIGH) ? is_active : !is_active; + + if (is_active) { + /* set initial clock polarity */ + if (spi->mode & SPI_CPOL) + sp->ioc_base |= AR71XX_SPI_IOC_CLK; + else + sp->ioc_base &= ~AR71XX_SPI_IOC_CLK; + + ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, sp->ioc_base); + } + + if (spi->chip_select) { + struct ath79_spi_controller_data *cdata = spi->controller_data; + + /* SPI is normally active-low */ + gpio_set_value(cdata->gpio, cs_high); + } else { + if (cs_high) + sp->ioc_base |= AR71XX_SPI_IOC_CS0; + else + sp->ioc_base &= ~AR71XX_SPI_IOC_CS0; + + ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, sp->ioc_base); + } + +} + +static void ath79_spi_enable(struct ath79_spi *sp) +{ + /* enable GPIO mode */ + ath79_spi_wr(sp, AR71XX_SPI_REG_FS, AR71XX_SPI_FS_GPIO); + + /* save CTRL register */ + sp->reg_ctrl = ath79_spi_rr(sp, AR71XX_SPI_REG_CTRL); + sp->ioc_base = ath79_spi_rr(sp, AR71XX_SPI_REG_IOC); + + /* TODO: setup speed? */ + ath79_spi_wr(sp, AR71XX_SPI_REG_CTRL, 0x43); +} + +static void ath79_spi_disable(struct ath79_spi *sp) +{ + /* restore CTRL register */ + ath79_spi_wr(sp, AR71XX_SPI_REG_CTRL, sp->reg_ctrl); + /* disable GPIO mode */ + ath79_spi_wr(sp, AR71XX_SPI_REG_FS, 0); +} + +static int ath79_spi_setup_cs(struct spi_device *spi) +{ + struct ath79_spi_controller_data *cdata; + int status; + + cdata = spi->controller_data; + if (spi->chip_select && !cdata) + return -EINVAL; + + status = 0; + if (spi->chip_select) { + unsigned long flags; + + flags = GPIOF_DIR_OUT; + if (spi->mode & SPI_CS_HIGH) + flags |= GPIOF_INIT_LOW; + else + flags |= GPIOF_INIT_HIGH; + + status = gpio_request_one(cdata->gpio, flags, + dev_name(&spi->dev)); + } + + return status; +} + +static void ath79_spi_cleanup_cs(struct spi_device *spi) +{ + if (spi->chip_select) { + struct ath79_spi_controller_data *cdata = spi->controller_data; + gpio_free(cdata->gpio); + } +} + +static int ath79_spi_setup(struct spi_device *spi) +{ + int status = 0; + + if (!spi->controller_state) { + status = ath79_spi_setup_cs(spi); + if (status) + return status; + } + + status = spi_bitbang_setup(spi); + if (status && !spi->controller_state) + ath79_spi_cleanup_cs(spi); + + return status; +} + +static void ath79_spi_cleanup(struct spi_device *spi) +{ + ath79_spi_cleanup_cs(spi); + spi_bitbang_cleanup(spi); +} + +static u32 ath79_spi_txrx_mode0(struct spi_device *spi, unsigned nsecs, + u32 word, u8 bits) +{ + struct ath79_spi *sp = ath79_spidev_to_sp(spi); + u32 ioc = sp->ioc_base; + + /* clock starts at inactive polarity */ + for (word <<= (32 - bits); likely(bits); bits--) { + u32 out; + + if (word & (1 << 31)) + out = ioc | AR71XX_SPI_IOC_DO; + else + out = ioc & ~AR71XX_SPI_IOC_DO; + + /* setup MSB (to slave) on trailing edge */ + ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, out); + ath79_spi_delay(sp, nsecs); + ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, out | AR71XX_SPI_IOC_CLK); + ath79_spi_delay(sp, nsecs); + if (bits == 1) + ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, out); + + word <<= 1; + } + + return ath79_spi_rr(sp, AR71XX_SPI_REG_RDS); +} + +static int ath79_spi_probe(struct platform_device *pdev) +{ + struct spi_master *master; + struct ath79_spi *sp; + struct ath79_spi_platform_data *pdata; + struct resource *r; + unsigned long rate; + int ret; + + master = spi_alloc_master(&pdev->dev, sizeof(*sp)); + if (master == NULL) { + dev_err(&pdev->dev, "failed to allocate spi master\n"); + return -ENOMEM; + } + + sp = spi_master_get_devdata(master); + platform_set_drvdata(pdev, sp); + + pdata = dev_get_platdata(&pdev->dev); + + master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32); + master->setup = ath79_spi_setup; + master->cleanup = ath79_spi_cleanup; + if (pdata) { + master->bus_num = pdata->bus_num; + master->num_chipselect = pdata->num_chipselect; + } + + sp->bitbang.master = master; + sp->bitbang.chipselect = ath79_spi_chipselect; + sp->bitbang.txrx_word[SPI_MODE_0] = ath79_spi_txrx_mode0; + sp->bitbang.setup_transfer = spi_bitbang_setup_transfer; + sp->bitbang.flags = SPI_CS_HIGH; + + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (r == NULL) { + ret = -ENOENT; + goto err_put_master; + } + + sp->base = devm_ioremap(&pdev->dev, r->start, resource_size(r)); + if (!sp->base) { + ret = -ENXIO; + goto err_put_master; + } + + sp->clk = devm_clk_get(&pdev->dev, "ahb"); + if (IS_ERR(sp->clk)) { + ret = PTR_ERR(sp->clk); + goto err_put_master; + } + + ret = clk_enable(sp->clk); + if (ret) + goto err_put_master; + + rate = DIV_ROUND_UP(clk_get_rate(sp->clk), MHZ); + if (!rate) { + ret = -EINVAL; + goto err_clk_disable; + } + + sp->rrw_delay = ATH79_SPI_RRW_DELAY_FACTOR / rate; + dev_dbg(&pdev->dev, "register read/write delay is %u nsecs\n", + sp->rrw_delay); + + ath79_spi_enable(sp); + ret = spi_bitbang_start(&sp->bitbang); + if (ret) + goto err_disable; + + return 0; + +err_disable: + ath79_spi_disable(sp); +err_clk_disable: + clk_disable(sp->clk); +err_put_master: + spi_master_put(sp->bitbang.master); + + return ret; +} + +static int ath79_spi_remove(struct platform_device *pdev) +{ + struct ath79_spi *sp = platform_get_drvdata(pdev); + + spi_bitbang_stop(&sp->bitbang); + ath79_spi_disable(sp); + clk_disable(sp->clk); + spi_master_put(sp->bitbang.master); + + return 0; +} + +static void ath79_spi_shutdown(struct platform_device *pdev) +{ + ath79_spi_remove(pdev); +} + +static struct platform_driver ath79_spi_driver = { + .probe = ath79_spi_probe, + .remove = ath79_spi_remove, + .shutdown = ath79_spi_shutdown, + .driver = { + .name = DRV_NAME, + }, +}; +module_platform_driver(ath79_spi_driver); + +MODULE_DESCRIPTION("SPI controller driver for Atheros AR71XX/AR724X/AR913X"); +MODULE_AUTHOR("Gabor Juhos "); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:" DRV_NAME); -- cgit 1.2.3-korg