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author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-07-22 14:52:44 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-07-22 14:52:44 -0700 |
commit | 7235dd74a4733d4b3651349b5261d2e06996427d (patch) | |
tree | 737d4141e77fdd6bfd8c9878ed4f7fe293e7b629 /drivers/spi/spi-ath79.c | |
parent | c7c8518498e82591d7784452f5674c3aeb4d079c (diff) | |
parent | 22a85e4cd51b49ec99703ddfdff8686d5442a093 (diff) | |
download | linux-7235dd74a4733d4b3651349b5261d2e06996427d.tar.gz linux-7235dd74a4733d4b3651349b5261d2e06996427d.tar.bz2 linux-7235dd74a4733d4b3651349b5261d2e06996427d.zip |
Merge branch 'spi/next' of git://git.secretlab.ca/git/linux-2.6
* 'spi/next' of git://git.secretlab.ca/git/linux-2.6: (34 commits)
spi/imx: add device tree probe support
spi/imx: copy gpio number passed by platform data into driver private data
spi/imx: use soc name in spi device type naming scheme
spi/imx: merge type SPI_IMX_VER_0_7 into SPI_IMX_VER_0_4
spi/imx: do not use spi_imx2_3 to name SPI_IMX_VER_2_3 function and macro
spi/imx: use mx21 to name SPI_IMX_VER_0_0 function and macro
spi/imx: do not make copy of spi_imx_devtype_data
spi/dw: Add spi number into spi irq desc
spi/tegra: Use engineering names in DT compatible property
spi/fsl_spi: fix CPM spi driver
mach-s3c2410: remove unused spi-gpio.h file
spi: remove obsolete spi-s3c24xx-gpio driver
mach-gta2: remove unused spi-gpio.h include
mach-qt2410: convert to spi_gpio
mach-jive: convert to spi_gpio
spi/pxa2xx: Remove unavailable ssp_type from documentation
spi/bfin_spi: uninline fat queue funcs
spi/bfin_spi: constify pin array
spi/bfin_spi: use structs for accessing hardware regs
spi/topcliff-pch: Support new device ML7223 IOH
...
Fix up trivial conflict in arch/arm/mach-ep93xx/Makefile
Diffstat (limited to 'drivers/spi/spi-ath79.c')
-rw-r--r-- | drivers/spi/spi-ath79.c | 292 |
1 files changed, 292 insertions, 0 deletions
diff --git a/drivers/spi/spi-ath79.c b/drivers/spi/spi-ath79.c new file mode 100644 index 000000000000..03019bf5a5e9 --- /dev/null +++ b/drivers/spi/spi-ath79.c @@ -0,0 +1,292 @@ +/* + * SPI controller driver for the Atheros AR71XX/AR724X/AR913X SoCs + * + * Copyright (C) 2009-2011 Gabor Juhos <juhosg@openwrt.org> + * + * 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 <linux/kernel.h> +#include <linux/init.h> +#include <linux/delay.h> +#include <linux/spinlock.h> +#include <linux/workqueue.h> +#include <linux/platform_device.h> +#include <linux/io.h> +#include <linux/spi/spi.h> +#include <linux/spi/spi_bitbang.h> +#include <linux/bitops.h> +#include <linux/gpio.h> + +#include <asm/mach-ath79/ar71xx_regs.h> +#include <asm/mach-ath79/ath79_spi_platform.h> + +#define DRV_NAME "ath79-spi" + +struct ath79_spi { + struct spi_bitbang bitbang; + u32 ioc_base; + u32 reg_ctrl; + void __iomem *base; +}; + +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 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 int ath79_spi_setup_cs(struct spi_device *spi) +{ + struct ath79_spi *sp = ath79_spidev_to_sp(spi); + struct ath79_spi_controller_data *cdata; + + cdata = spi->controller_data; + if (spi->chip_select && !cdata) + return -EINVAL; + + /* 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); + + if (spi->chip_select) { + int status = 0; + + status = gpio_request(cdata->gpio, dev_name(&spi->dev)); + if (status) + return status; + + status = gpio_direction_output(cdata->gpio, + spi->mode & SPI_CS_HIGH); + if (status) { + gpio_free(cdata->gpio); + return status; + } + } else { + if (spi->mode & SPI_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); + } + + return 0; +} + +static void ath79_spi_cleanup_cs(struct spi_device *spi) +{ + struct ath79_spi *sp = ath79_spidev_to_sp(spi); + + if (spi->chip_select) { + struct ath79_spi_controller_data *cdata = spi->controller_data; + gpio_free(cdata->gpio); + } + + /* 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(struct spi_device *spi) +{ + int status = 0; + + if (spi->bits_per_word > 32) + return -EINVAL; + + 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_wr(sp, AR71XX_SPI_REG_IOC, out | AR71XX_SPI_IOC_CLK); + + word <<= 1; + } + + return ath79_spi_rr(sp, AR71XX_SPI_REG_RDS); +} + +static __devinit 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; + 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 = pdev->dev.platform_data; + + master->setup = ath79_spi_setup; + master->cleanup = ath79_spi_cleanup; + if (pdata) { + master->bus_num = pdata->bus_num; + master->num_chipselect = pdata->num_chipselect; + } else { + master->bus_num = -1; + master->num_chipselect = 1; + } + + sp->bitbang.master = spi_master_get(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 = ioremap(r->start, resource_size(r)); + if (!sp->base) { + ret = -ENXIO; + goto err_put_master; + } + + ret = spi_bitbang_start(&sp->bitbang); + if (ret) + goto err_unmap; + + return 0; + +err_unmap: + iounmap(sp->base); +err_put_master: + platform_set_drvdata(pdev, NULL); + spi_master_put(sp->bitbang.master); + + return ret; +} + +static __devexit int ath79_spi_remove(struct platform_device *pdev) +{ + struct ath79_spi *sp = platform_get_drvdata(pdev); + + spi_bitbang_stop(&sp->bitbang); + iounmap(sp->base); + platform_set_drvdata(pdev, NULL); + spi_master_put(sp->bitbang.master); + + return 0; +} + +static struct platform_driver ath79_spi_driver = { + .probe = ath79_spi_probe, + .remove = __devexit_p(ath79_spi_remove), + .driver = { + .name = DRV_NAME, + .owner = THIS_MODULE, + }, +}; + +static __init int ath79_spi_init(void) +{ + return platform_driver_register(&ath79_spi_driver); +} +module_init(ath79_spi_init); + +static __exit void ath79_spi_exit(void) +{ + platform_driver_unregister(&ath79_spi_driver); +} +module_exit(ath79_spi_exit); + +MODULE_DESCRIPTION("SPI controller driver for Atheros AR71XX/AR724X/AR913X"); +MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:" DRV_NAME); |