diff options
Diffstat (limited to 'drivers/spi/spi_s3c24xx.c')
| -rw-r--r-- | drivers/spi/spi_s3c24xx.c | 746 |
1 files changed, 0 insertions, 746 deletions
diff --git a/drivers/spi/spi_s3c24xx.c b/drivers/spi/spi_s3c24xx.c deleted file mode 100644 index 151a95e4065..00000000000 --- a/drivers/spi/spi_s3c24xx.c +++ /dev/null @@ -1,746 +0,0 @@ -/* linux/drivers/spi/spi_s3c24xx.c - * - * Copyright (c) 2006 Ben Dooks - * Copyright 2006-2009 Simtec Electronics - * Ben Dooks <ben@simtec.co.uk> - * - * 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/init.h> -#include <linux/spinlock.h> -#include <linux/workqueue.h> -#include <linux/interrupt.h> -#include <linux/delay.h> -#include <linux/errno.h> -#include <linux/err.h> -#include <linux/clk.h> -#include <linux/platform_device.h> -#include <linux/gpio.h> -#include <linux/io.h> -#include <linux/slab.h> - -#include <linux/spi/spi.h> -#include <linux/spi/spi_bitbang.h> - -#include <plat/regs-spi.h> -#include <mach/spi.h> - -#include <plat/fiq.h> -#include <asm/fiq.h> - -#include "spi_s3c24xx_fiq.h" - -/** - * s3c24xx_spi_devstate - per device data - * @hz: Last frequency calculated for @sppre field. - * @mode: Last mode setting for the @spcon field. - * @spcon: Value to write to the SPCON register. - * @sppre: Value to write to the SPPRE register. - */ -struct s3c24xx_spi_devstate { - unsigned int hz; - unsigned int mode; - u8 spcon; - u8 sppre; -}; - -enum spi_fiq_mode { - FIQ_MODE_NONE = 0, - FIQ_MODE_TX = 1, - FIQ_MODE_RX = 2, - FIQ_MODE_TXRX = 3, -}; - -struct s3c24xx_spi { - /* bitbang has to be first */ - struct spi_bitbang bitbang; - struct completion done; - - void __iomem *regs; - int irq; - int len; - int count; - - struct fiq_handler fiq_handler; - enum spi_fiq_mode fiq_mode; - unsigned char fiq_inuse; - unsigned char fiq_claimed; - - void (*set_cs)(struct s3c2410_spi_info *spi, - int cs, int pol); - - /* data buffers */ - const unsigned char *tx; - unsigned char *rx; - - struct clk *clk; - struct resource *ioarea; - struct spi_master *master; - struct spi_device *curdev; - struct device *dev; - struct s3c2410_spi_info *pdata; -}; - - -#define SPCON_DEFAULT (S3C2410_SPCON_MSTR | S3C2410_SPCON_SMOD_INT) -#define SPPIN_DEFAULT (S3C2410_SPPIN_KEEP) - -static inline struct s3c24xx_spi *to_hw(struct spi_device *sdev) -{ - return spi_master_get_devdata(sdev->master); -} - -static void s3c24xx_spi_gpiocs(struct s3c2410_spi_info *spi, int cs, int pol) -{ - gpio_set_value(spi->pin_cs, pol); -} - -static void s3c24xx_spi_chipsel(struct spi_device *spi, int value) -{ - struct s3c24xx_spi_devstate *cs = spi->controller_state; - struct s3c24xx_spi *hw = to_hw(spi); - unsigned int cspol = spi->mode & SPI_CS_HIGH ? 1 : 0; - - /* change the chipselect state and the state of the spi engine clock */ - - switch (value) { - case BITBANG_CS_INACTIVE: - hw->set_cs(hw->pdata, spi->chip_select, cspol^1); - writeb(cs->spcon, hw->regs + S3C2410_SPCON); - break; - - case BITBANG_CS_ACTIVE: - writeb(cs->spcon | S3C2410_SPCON_ENSCK, - hw->regs + S3C2410_SPCON); - hw->set_cs(hw->pdata, spi->chip_select, cspol); - break; - } -} - -static int s3c24xx_spi_update_state(struct spi_device *spi, - struct spi_transfer *t) -{ - struct s3c24xx_spi *hw = to_hw(spi); - struct s3c24xx_spi_devstate *cs = spi->controller_state; - unsigned int bpw; - unsigned int hz; - unsigned int div; - unsigned long clk; - - bpw = t ? t->bits_per_word : spi->bits_per_word; - hz = t ? t->speed_hz : spi->max_speed_hz; - - if (!bpw) - bpw = 8; - - if (!hz) - hz = spi->max_speed_hz; - - if (bpw != 8) { - dev_err(&spi->dev, "invalid bits-per-word (%d)\n", bpw); - return -EINVAL; - } - - if (spi->mode != cs->mode) { - u8 spcon = SPCON_DEFAULT | S3C2410_SPCON_ENSCK; - - if (spi->mode & SPI_CPHA) - spcon |= S3C2410_SPCON_CPHA_FMTB; - - if (spi->mode & SPI_CPOL) - spcon |= S3C2410_SPCON_CPOL_HIGH; - - cs->mode = spi->mode; - cs->spcon = spcon; - } - - if (cs->hz != hz) { - clk = clk_get_rate(hw->clk); - div = DIV_ROUND_UP(clk, hz * 2) - 1; - - if (div > 255) - div = 255; - - dev_dbg(&spi->dev, "pre-scaler=%d (wanted %d, got %ld)\n", - div, hz, clk / (2 * (div + 1))); - - cs->hz = hz; - cs->sppre = div; - } - - return 0; -} - -static int s3c24xx_spi_setupxfer(struct spi_device *spi, - struct spi_transfer *t) -{ - struct s3c24xx_spi_devstate *cs = spi->controller_state; - struct s3c24xx_spi *hw = to_hw(spi); - int ret; - - ret = s3c24xx_spi_update_state(spi, t); - if (!ret) - writeb(cs->sppre, hw->regs + S3C2410_SPPRE); - - return ret; -} - -static int s3c24xx_spi_setup(struct spi_device *spi) -{ - struct s3c24xx_spi_devstate *cs = spi->controller_state; - struct s3c24xx_spi *hw = to_hw(spi); - int ret; - - /* allocate settings on the first call */ - if (!cs) { - cs = kzalloc(sizeof(struct s3c24xx_spi_devstate), GFP_KERNEL); - if (!cs) { - dev_err(&spi->dev, "no memory for controller state\n"); - return -ENOMEM; - } - - cs->spcon = SPCON_DEFAULT; - cs->hz = -1; - spi->controller_state = cs; - } - - /* initialise the state from the device */ - ret = s3c24xx_spi_update_state(spi, NULL); - if (ret) - return ret; - - spin_lock(&hw->bitbang.lock); - if (!hw->bitbang.busy) { - hw->bitbang.chipselect(spi, BITBANG_CS_INACTIVE); - /* need to ndelay for 0.5 clocktick ? */ - } - spin_unlock(&hw->bitbang.lock); - - return 0; -} - -static void s3c24xx_spi_cleanup(struct spi_device *spi) -{ - kfree(spi->controller_state); -} - -static inline unsigned int hw_txbyte(struct s3c24xx_spi *hw, int count) -{ - return hw->tx ? hw->tx[count] : 0; -} - -#ifdef CONFIG_SPI_S3C24XX_FIQ -/* Support for FIQ based pseudo-DMA to improve the transfer speed. - * - * This code uses the assembly helper in spi_s3c24xx_spi.S which is - * used by the FIQ core to move data between main memory and the peripheral - * block. Since this is code running on the processor, there is no problem - * with cache coherency of the buffers, so we can use any buffer we like. - */ - -/** - * struct spi_fiq_code - FIQ code and header - * @length: The length of the code fragment, excluding this header. - * @ack_offset: The offset from @data to the word to place the IRQ ACK bit at. - * @data: The code itself to install as a FIQ handler. - */ -struct spi_fiq_code { - u32 length; - u32 ack_offset; - u8 data[0]; -}; - -extern struct spi_fiq_code s3c24xx_spi_fiq_txrx; -extern struct spi_fiq_code s3c24xx_spi_fiq_tx; -extern struct spi_fiq_code s3c24xx_spi_fiq_rx; - -/** - * ack_bit - turn IRQ into IRQ acknowledgement bit - * @irq: The interrupt number - * - * Returns the bit to write to the interrupt acknowledge register. - */ -static inline u32 ack_bit(unsigned int irq) -{ - return 1 << (irq - IRQ_EINT0); -} - -/** - * s3c24xx_spi_tryfiq - attempt to claim and setup FIQ for transfer - * @hw: The hardware state. - * - * Claim the FIQ handler (only one can be active at any one time) and - * then setup the correct transfer code for this transfer. - * - * This call updates all the necessary state information if successful, - * so the caller does not need to do anything more than start the transfer - * as normal, since the IRQ will have been re-routed to the FIQ handler. -*/ -void s3c24xx_spi_tryfiq(struct s3c24xx_spi *hw) -{ - struct pt_regs regs; - enum spi_fiq_mode mode; - struct spi_fiq_code *code; - int ret; - - if (!hw->fiq_claimed) { - /* try and claim fiq if we haven't got it, and if not - * then return and simply use another transfer method */ - - ret = claim_fiq(&hw->fiq_handler); - if (ret) - return; - } - - if (hw->tx && !hw->rx) - mode = FIQ_MODE_TX; - else if (hw->rx && !hw->tx) - mode = FIQ_MODE_RX; - else - mode = FIQ_MODE_TXRX; - - regs.uregs[fiq_rspi] = (long)hw->regs; - regs.uregs[fiq_rrx] = (long)hw->rx; - regs.uregs[fiq_rtx] = (long)hw->tx + 1; - regs.uregs[fiq_rcount] = hw->len - 1; - regs.uregs[fiq_rirq] = (long)S3C24XX_VA_IRQ; - - set_fiq_regs(®s); - - if (hw->fiq_mode != mode) { - u32 *ack_ptr; - - hw->fiq_mode = mode; - - switch (mode) { - case FIQ_MODE_TX: - code = &s3c24xx_spi_fiq_tx; - break; - case FIQ_MODE_RX: - code = &s3c24xx_spi_fiq_rx; - break; - case FIQ_MODE_TXRX: - code = &s3c24xx_spi_fiq_txrx; - break; - default: - code = NULL; - } - - BUG_ON(!code); - - ack_ptr = (u32 *)&code->data[code->ack_offset]; - *ack_ptr = ack_bit(hw->irq); - - set_fiq_handler(&code->data, code->length); - } - - s3c24xx_set_fiq(hw->irq, true); - - hw->fiq_mode = mode; - hw->fiq_inuse = 1; -} - -/** - * s3c24xx_spi_fiqop - FIQ core code callback - * @pw: Data registered with the handler - * @release: Whether this is a release or a return. - * - * Called by the FIQ code when another module wants to use the FIQ, so - * return whether we are currently using this or not and then update our - * internal state. - */ -static int s3c24xx_spi_fiqop(void *pw, int release) -{ - struct s3c24xx_spi *hw = pw; - int ret = 0; - - if (release) { - if (hw->fiq_inuse) - ret = -EBUSY; - - /* note, we do not need to unroute the FIQ, as the FIQ - * vector code de-routes it to signal the end of transfer */ - - hw->fiq_mode = FIQ_MODE_NONE; - hw->fiq_claimed = 0; - } else { - hw->fiq_claimed = 1; - } - - return ret; -} - -/** - * s3c24xx_spi_initfiq - setup the information for the FIQ core - * @hw: The hardware state. - * - * Setup the fiq_handler block to pass to the FIQ core. - */ -static inline void s3c24xx_spi_initfiq(struct s3c24xx_spi *hw) -{ - hw->fiq_handler.dev_id = hw; - hw->fiq_handler.name = dev_name(hw->dev); - hw->fiq_handler.fiq_op = s3c24xx_spi_fiqop; -} - -/** - * s3c24xx_spi_usefiq - return if we should be using FIQ. - * @hw: The hardware state. - * - * Return true if the platform data specifies whether this channel is - * allowed to use the FIQ. - */ -static inline bool s3c24xx_spi_usefiq(struct s3c24xx_spi *hw) -{ - return hw->pdata->use_fiq; -} - -/** - * s3c24xx_spi_usingfiq - return if channel is using FIQ - * @spi: The hardware state. - * - * Return whether the channel is currently using the FIQ (separate from - * whether the FIQ is claimed). - */ -static inline bool s3c24xx_spi_usingfiq(struct s3c24xx_spi *spi) -{ - return spi->fiq_inuse; -} -#else - -static inline void s3c24xx_spi_initfiq(struct s3c24xx_spi *s) { } -static inline void s3c24xx_spi_tryfiq(struct s3c24xx_spi *s) { } -static inline bool s3c24xx_spi_usefiq(struct s3c24xx_spi *s) { return false; } -static inline bool s3c24xx_spi_usingfiq(struct s3c24xx_spi *s) { return false; } - -#endif /* CONFIG_SPI_S3C24XX_FIQ */ - -static int s3c24xx_spi_txrx(struct spi_device *spi, struct spi_transfer *t) -{ - struct s3c24xx_spi *hw = to_hw(spi); - - hw->tx = t->tx_buf; - hw->rx = t->rx_buf; - hw->len = t->len; - hw->count = 0; - - init_completion(&hw->done); - - hw->fiq_inuse = 0; - if (s3c24xx_spi_usefiq(hw) && t->len >= 3) - s3c24xx_spi_tryfiq(hw); - - /* send the first byte */ - writeb(hw_txbyte(hw, 0), hw->regs + S3C2410_SPTDAT); - - wait_for_completion(&hw->done); - return hw->count; -} - -static irqreturn_t s3c24xx_spi_irq(int irq, void *dev) -{ - struct s3c24xx_spi *hw = dev; - unsigned int spsta = readb(hw->regs + S3C2410_SPSTA); - unsigned int count = hw->count; - - if (spsta & S3C2410_SPSTA_DCOL) { - dev_dbg(hw->dev, "data-collision\n"); - complete(&hw->done); - goto irq_done; - } - - if (!(spsta & S3C2410_SPSTA_READY)) { - dev_dbg(hw->dev, "spi not ready for tx?\n"); - complete(&hw->done); - goto irq_done; - } - - if (!s3c24xx_spi_usingfiq(hw)) { - hw->count++; - - if (hw->rx) - hw->rx[count] = readb(hw->regs + S3C2410_SPRDAT); - - count++; - - if (count < hw->len) - writeb(hw_txbyte(hw, count), hw->regs + S3C2410_SPTDAT); - else - complete(&hw->done); - } else { - hw->count = hw->len; - hw->fiq_inuse = 0; - - if (hw->rx) - hw->rx[hw->len-1] = readb(hw->regs + S3C2410_SPRDAT); - - complete(&hw->done); - } - - irq_done: - return IRQ_HANDLED; -} - -static void s3c24xx_spi_initialsetup(struct s3c24xx_spi *hw) -{ - /* for the moment, permanently enable the clock */ - - clk_enable(hw->clk); - - /* program defaults into the registers */ - - writeb(0xff, hw->regs + S3C2410_SPPRE); - writeb(SPPIN_DEFAULT, hw->regs + S3C2410_SPPIN); - writeb(SPCON_DEFAULT, hw->regs + S3C2410_SPCON); - - if (hw->pdata) { - if (hw->set_cs == s3c24xx_spi_gpiocs) - gpio_direction_output(hw->pdata->pin_cs, 1); - - if (hw->pdata->gpio_setup) - hw->pdata->gpio_setup(hw->pdata, 1); - } -} - -static int __init s3c24xx_spi_probe(struct platform_device *pdev) -{ - struct s3c2410_spi_info *pdata; - struct s3c24xx_spi *hw; - struct spi_master *master; - struct resource *res; - int err = 0; - - master = spi_alloc_master(&pdev->dev, sizeof(struct s3c24xx_spi)); - if (master == NULL) { - dev_err(&pdev->dev, "No memory for spi_master\n"); - err = -ENOMEM; - goto err_nomem; - } - - hw = spi_master_get_devdata(master); - memset(hw, 0, sizeof(struct s3c24xx_spi)); - - hw->master = spi_master_get(master); - hw->pdata = pdata = pdev->dev.platform_data; - hw->dev = &pdev->dev; - - if (pdata == NULL) { - dev_err(&pdev->dev, "No platform data supplied\n"); - err = -ENOENT; - goto err_no_pdata; - } - - platform_set_drvdata(pdev, hw); - init_completion(&hw->done); - - /* initialise fiq handler */ - - s3c24xx_spi_initfiq(hw); - - /* setup the master state. */ - - /* the spi->mode bits understood by this driver: */ - master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH; - - master->num_chipselect = hw->pdata->num_cs; - master->bus_num = pdata->bus_num; - - /* setup the state for the bitbang driver */ - - hw->bitbang.master = hw->master; - hw->bitbang.setup_transfer = s3c24xx_spi_setupxfer; - hw->bitbang.chipselect = s3c24xx_spi_chipsel; - hw->bitbang.txrx_bufs = s3c24xx_spi_txrx; - - hw->master->setup = s3c24xx_spi_setup; - hw->master->cleanup = s3c24xx_spi_cleanup; - - dev_dbg(hw->dev, "bitbang at %p\n", &hw->bitbang); - - /* find and map our resources */ - - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (res == NULL) { - dev_err(&pdev->dev, "Cannot get IORESOURCE_MEM\n"); - err = -ENOENT; - goto err_no_iores; - } - - hw->ioarea = request_mem_region(res->start, resource_size(res), - pdev->name); - - if (hw->ioarea == NULL) { - dev_err(&pdev->dev, "Cannot reserve region\n"); - err = -ENXIO; - goto err_no_iores; - } - - hw->regs = ioremap(res->start, resource_size(res)); - if (hw->regs == NULL) { - dev_err(&pdev->dev, "Cannot map IO\n"); - err = -ENXIO; - goto err_no_iomap; - } - - hw->irq = platform_get_irq(pdev, 0); - if (hw->irq < 0) { - dev_err(&pdev->dev, "No IRQ specified\n"); - err = -ENOENT; - goto err_no_irq; - } - - err = request_irq(hw->irq, s3c24xx_spi_irq, 0, pdev->name, hw); - if (err) { - dev_err(&pdev->dev, "Cannot claim IRQ\n"); - goto err_no_irq; - } - - hw->clk = clk_get(&pdev->dev, "spi"); - if (IS_ERR(hw->clk)) { - dev_err(&pdev->dev, "No clock for device\n"); - err = PTR_ERR(hw->clk); - goto err_no_clk; - } - - /* setup any gpio we can */ - - if (!pdata->set_cs) { - if (pdata->pin_cs < 0) { - dev_err(&pdev->dev, "No chipselect pin\n"); - goto err_register; - } - - err = gpio_request(pdata->pin_cs, dev_name(&pdev->dev)); - if (err) { - dev_err(&pdev->dev, "Failed to get gpio for cs\n"); - goto err_register; - } - - hw->set_cs = s3c24xx_spi_gpiocs; - gpio_direction_output(pdata->pin_cs, 1); - } else - hw->set_cs = pdata->set_cs; - - s3c24xx_spi_initialsetup(hw); - - /* register our spi controller */ - - err = spi_bitbang_start(&hw->bitbang); - if (err) { - dev_err(&pdev->dev, "Failed to register SPI master\n"); - goto err_register; - } - - return 0; - - err_register: - if (hw->set_cs == s3c24xx_spi_gpiocs) - gpio_free(pdata->pin_cs); - - clk_disable(hw->clk); - clk_put(hw->clk); - - err_no_clk: - free_irq(hw->irq, hw); - - err_no_irq: - iounmap(hw->regs); - - err_no_iomap: - release_resource(hw->ioarea); - kfree(hw->ioarea); - - err_no_iores: - err_no_pdata: - spi_master_put(hw->master); - - err_nomem: - return err; -} - -static int __exit s3c24xx_spi_remove(struct platform_device *dev) -{ - struct s3c24xx_spi *hw = platform_get_drvdata(dev); - - platform_set_drvdata(dev, NULL); - - spi_unregister_master(hw->master); - - clk_disable(hw->clk); - clk_put(hw->clk); - - free_irq(hw->irq, hw); - iounmap(hw->regs); - - if (hw->set_cs == s3c24xx_spi_gpiocs) - gpio_free(hw->pdata->pin_cs); - - release_resource(hw->ioarea); - kfree(hw->ioarea); - - spi_master_put(hw->master); - return 0; -} - - -#ifdef CONFIG_PM - -static int s3c24xx_spi_suspend(struct device *dev) -{ - struct s3c24xx_spi *hw = platform_get_drvdata(to_platform_device(dev)); - - if (hw->pdata && hw->pdata->gpio_setup) - hw->pdata->gpio_setup(hw->pdata, 0); - - clk_disable(hw->clk); - return 0; -} - -static int s3c24xx_spi_resume(struct device *dev) -{ - struct s3c24xx_spi *hw = platform_get_drvdata(to_platform_device(dev)); - - s3c24xx_spi_initialsetup(hw); - return 0; -} - -static const struct dev_pm_ops s3c24xx_spi_pmops = { - .suspend = s3c24xx_spi_suspend, - .resume = s3c24xx_spi_resume, -}; - -#define S3C24XX_SPI_PMOPS &s3c24xx_spi_pmops -#else -#define S3C24XX_SPI_PMOPS NULL -#endif /* CONFIG_PM */ - -MODULE_ALIAS("platform:s3c2410-spi"); -static struct platform_driver s3c24xx_spi_driver = { - .remove = __exit_p(s3c24xx_spi_remove), - .driver = { - .name = "s3c2410-spi", - .owner = THIS_MODULE, - .pm = S3C24XX_SPI_PMOPS, - }, -}; - -static int __init s3c24xx_spi_init(void) -{ - return platform_driver_probe(&s3c24xx_spi_driver, s3c24xx_spi_probe); -} - -static void __exit s3c24xx_spi_exit(void) -{ - platform_driver_unregister(&s3c24xx_spi_driver); -} - -module_init(s3c24xx_spi_init); -module_exit(s3c24xx_spi_exit); - -MODULE_DESCRIPTION("S3C24XX SPI Driver"); -MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>"); -MODULE_LICENSE("GPL"); |