diff options
Diffstat (limited to 'drivers/spi/spi_nuc900.c')
| -rw-r--r-- | drivers/spi/spi_nuc900.c | 504 |
1 files changed, 504 insertions, 0 deletions
diff --git a/drivers/spi/spi_nuc900.c b/drivers/spi/spi_nuc900.c new file mode 100644 index 00000000000..b319f9bf9b9 --- /dev/null +++ b/drivers/spi/spi_nuc900.c @@ -0,0 +1,504 @@ +/* linux/drivers/spi/spi_nuc900.c + * + * Copyright (c) 2009 Nuvoton technology. + * Wan ZongShun <mcuos.com@gmail.com> + * + * 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/device.h> +#include <linux/platform_device.h> +#include <linux/gpio.h> +#include <linux/io.h> + +#include <linux/spi/spi.h> +#include <linux/spi/spi_bitbang.h> + +#include <mach/nuc900_spi.h> + +/* usi registers offset */ +#define USI_CNT 0x00 +#define USI_DIV 0x04 +#define USI_SSR 0x08 +#define USI_RX0 0x10 +#define USI_TX0 0x10 + +/* usi register bit */ +#define ENINT (0x01 << 17) +#define ENFLG (0x01 << 16) +#define TXNUM (0x03 << 8) +#define TXNEG (0x01 << 2) +#define RXNEG (0x01 << 1) +#define LSB (0x01 << 10) +#define SELECTLEV (0x01 << 2) +#define SELECTPOL (0x01 << 31) +#define SELECTSLAVE 0x01 +#define GOBUSY 0x01 + +struct nuc900_spi { + struct spi_bitbang bitbang; + struct completion done; + void __iomem *regs; + int irq; + int len; + int count; + 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 nuc900_spi_info *pdata; + spinlock_t lock; + struct resource *res; +}; + +static inline struct nuc900_spi *to_hw(struct spi_device *sdev) +{ + return spi_master_get_devdata(sdev->master); +} + +static void nuc900_slave_select(struct spi_device *spi, unsigned int ssr) +{ + struct nuc900_spi *hw = to_hw(spi); + unsigned int val; + unsigned int cs = spi->mode & SPI_CS_HIGH ? 1 : 0; + unsigned int cpol = spi->mode & SPI_CPOL ? 1 : 0; + unsigned long flags; + + spin_lock_irqsave(&hw->lock, flags); + + val = __raw_readl(hw->regs + USI_SSR); + + if (!cs) + val &= ~SELECTLEV; + else + val |= SELECTLEV; + + if (!ssr) + val &= ~SELECTSLAVE; + else + val |= SELECTSLAVE; + + __raw_writel(val, hw->regs + USI_SSR); + + val = __raw_readl(hw->regs + USI_CNT); + + if (!cpol) + val &= ~SELECTPOL; + else + val |= SELECTPOL; + + __raw_writel(val, hw->regs + USI_CNT); + + spin_unlock_irqrestore(&hw->lock, flags); +} + +static void nuc900_spi_chipsel(struct spi_device *spi, int value) +{ + switch (value) { + case BITBANG_CS_INACTIVE: + nuc900_slave_select(spi, 0); + break; + + case BITBANG_CS_ACTIVE: + nuc900_slave_select(spi, 1); + break; + } +} + +static void nuc900_spi_setup_txnum(struct nuc900_spi *hw, + unsigned int txnum) +{ + unsigned int val; + unsigned long flags; + + spin_lock_irqsave(&hw->lock, flags); + + val = __raw_readl(hw->regs + USI_CNT); + + if (!txnum) + val &= ~TXNUM; + else + val |= txnum << 0x08; + + __raw_writel(val, hw->regs + USI_CNT); + + spin_unlock_irqrestore(&hw->lock, flags); + +} + +static void nuc900_spi_setup_txbitlen(struct nuc900_spi *hw, + unsigned int txbitlen) +{ + unsigned int val; + unsigned long flags; + + spin_lock_irqsave(&hw->lock, flags); + + val = __raw_readl(hw->regs + USI_CNT); + + val |= (txbitlen << 0x03); + + __raw_writel(val, hw->regs + USI_CNT); + + spin_unlock_irqrestore(&hw->lock, flags); +} + +static void nuc900_spi_gobusy(struct nuc900_spi *hw) +{ + unsigned int val; + unsigned long flags; + + spin_lock_irqsave(&hw->lock, flags); + + val = __raw_readl(hw->regs + USI_CNT); + + val |= GOBUSY; + + __raw_writel(val, hw->regs + USI_CNT); + + spin_unlock_irqrestore(&hw->lock, flags); +} + +static int nuc900_spi_setupxfer(struct spi_device *spi, + struct spi_transfer *t) +{ + return 0; +} + +static int nuc900_spi_setup(struct spi_device *spi) +{ + return 0; +} + +static inline unsigned int hw_txbyte(struct nuc900_spi *hw, int count) +{ + return hw->tx ? hw->tx[count] : 0; +} + +static int nuc900_spi_txrx(struct spi_device *spi, struct spi_transfer *t) +{ + struct nuc900_spi *hw = to_hw(spi); + + hw->tx = t->tx_buf; + hw->rx = t->rx_buf; + hw->len = t->len; + hw->count = 0; + + __raw_writel(hw_txbyte(hw, 0x0), hw->regs + USI_TX0); + + nuc900_spi_gobusy(hw); + + wait_for_completion(&hw->done); + + return hw->count; +} + +static irqreturn_t nuc900_spi_irq(int irq, void *dev) +{ + struct nuc900_spi *hw = dev; + unsigned int status; + unsigned int count = hw->count; + + status = __raw_readl(hw->regs + USI_CNT); + __raw_writel(status, hw->regs + USI_CNT); + + if (status & ENFLG) { + hw->count++; + + if (hw->rx) + hw->rx[count] = __raw_readl(hw->regs + USI_RX0); + count++; + + if (count < hw->len) { + __raw_writel(hw_txbyte(hw, count), hw->regs + USI_TX0); + nuc900_spi_gobusy(hw); + } else { + complete(&hw->done); + } + + return IRQ_HANDLED; + } + + complete(&hw->done); + return IRQ_HANDLED; +} + +static void nuc900_tx_edge(struct nuc900_spi *hw, unsigned int edge) +{ + unsigned int val; + unsigned long flags; + + spin_lock_irqsave(&hw->lock, flags); + + val = __raw_readl(hw->regs + USI_CNT); + + if (edge) + val |= TXNEG; + else + val &= ~TXNEG; + __raw_writel(val, hw->regs + USI_CNT); + + spin_unlock_irqrestore(&hw->lock, flags); +} + +static void nuc900_rx_edge(struct nuc900_spi *hw, unsigned int edge) +{ + unsigned int val; + unsigned long flags; + + spin_lock_irqsave(&hw->lock, flags); + + val = __raw_readl(hw->regs + USI_CNT); + + if (edge) + val |= RXNEG; + else + val &= ~RXNEG; + __raw_writel(val, hw->regs + USI_CNT); + + spin_unlock_irqrestore(&hw->lock, flags); +} + +static void nuc900_send_first(struct nuc900_spi *hw, unsigned int lsb) +{ + unsigned int val; + unsigned long flags; + + spin_lock_irqsave(&hw->lock, flags); + + val = __raw_readl(hw->regs + USI_CNT); + + if (lsb) + val |= LSB; + else + val &= ~LSB; + __raw_writel(val, hw->regs + USI_CNT); + + spin_unlock_irqrestore(&hw->lock, flags); +} + +static void nuc900_set_sleep(struct nuc900_spi *hw, unsigned int sleep) +{ + unsigned int val; + unsigned long flags; + + spin_lock_irqsave(&hw->lock, flags); + + val = __raw_readl(hw->regs + USI_CNT); + + if (sleep) + val |= (sleep << 12); + else + val &= ~(0x0f << 12); + __raw_writel(val, hw->regs + USI_CNT); + + spin_unlock_irqrestore(&hw->lock, flags); +} + +static void nuc900_enable_int(struct nuc900_spi *hw) +{ + unsigned int val; + unsigned long flags; + + spin_lock_irqsave(&hw->lock, flags); + + val = __raw_readl(hw->regs + USI_CNT); + + val |= ENINT; + + __raw_writel(val, hw->regs + USI_CNT); + + spin_unlock_irqrestore(&hw->lock, flags); +} + +static void nuc900_set_divider(struct nuc900_spi *hw) +{ + __raw_writel(hw->pdata->divider, hw->regs + USI_DIV); +} + +static void nuc900_init_spi(struct nuc900_spi *hw) +{ + clk_enable(hw->clk); + spin_lock_init(&hw->lock); + + nuc900_tx_edge(hw, hw->pdata->txneg); + nuc900_rx_edge(hw, hw->pdata->rxneg); + nuc900_send_first(hw, hw->pdata->lsb); + nuc900_set_sleep(hw, hw->pdata->sleep); + nuc900_spi_setup_txbitlen(hw, hw->pdata->txbitlen); + nuc900_spi_setup_txnum(hw, hw->pdata->txnum); + nuc900_set_divider(hw); + nuc900_enable_int(hw); +} + +static int __devinit nuc900_spi_probe(struct platform_device *pdev) +{ + struct nuc900_spi *hw; + struct spi_master *master; + int err = 0; + + master = spi_alloc_master(&pdev->dev, sizeof(struct nuc900_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 nuc900_spi)); + + hw->master = spi_master_get(master); + hw->pdata = pdev->dev.platform_data; + hw->dev = &pdev->dev; + + if (hw->pdata == NULL) { + dev_err(&pdev->dev, "No platform data supplied\n"); + err = -ENOENT; + goto err_pdata; + } + + platform_set_drvdata(pdev, hw); + init_completion(&hw->done); + + master->mode_bits = SPI_MODE_0; + master->num_chipselect = hw->pdata->num_cs; + master->bus_num = hw->pdata->bus_num; + hw->bitbang.master = hw->master; + hw->bitbang.setup_transfer = nuc900_spi_setupxfer; + hw->bitbang.chipselect = nuc900_spi_chipsel; + hw->bitbang.txrx_bufs = nuc900_spi_txrx; + hw->bitbang.master->setup = nuc900_spi_setup; + + hw->res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (hw->res == NULL) { + dev_err(&pdev->dev, "Cannot get IORESOURCE_MEM\n"); + err = -ENOENT; + goto err_pdata; + } + + hw->ioarea = request_mem_region(hw->res->start, + resource_size(hw->res), pdev->name); + + if (hw->ioarea == NULL) { + dev_err(&pdev->dev, "Cannot reserve region\n"); + err = -ENXIO; + goto err_pdata; + } + + hw->regs = ioremap(hw->res->start, resource_size(hw->res)); + if (hw->regs == NULL) { + dev_err(&pdev->dev, "Cannot map IO\n"); + err = -ENXIO; + goto err_iomap; + } + + hw->irq = platform_get_irq(pdev, 0); + if (hw->irq < 0) { + dev_err(&pdev->dev, "No IRQ specified\n"); + err = -ENOENT; + goto err_irq; + } + + err = request_irq(hw->irq, nuc900_spi_irq, 0, pdev->name, hw); + if (err) { + dev_err(&pdev->dev, "Cannot claim IRQ\n"); + goto err_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_clk; + } + + mfp_set_groupg(&pdev->dev); + nuc900_init_spi(hw); + + 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: + clk_disable(hw->clk); + clk_put(hw->clk); +err_clk: + free_irq(hw->irq, hw); +err_irq: + iounmap(hw->regs); +err_iomap: + release_mem_region(hw->res->start, resource_size(hw->res)); + kfree(hw->ioarea); +err_pdata: + spi_master_put(hw->master);; + +err_nomem: + return err; +} + +static int __devexit nuc900_spi_remove(struct platform_device *dev) +{ + struct nuc900_spi *hw = platform_get_drvdata(dev); + + free_irq(hw->irq, hw); + + platform_set_drvdata(dev, NULL); + + spi_unregister_master(hw->master); + + clk_disable(hw->clk); + clk_put(hw->clk); + + iounmap(hw->regs); + + release_mem_region(hw->res->start, resource_size(hw->res)); + kfree(hw->ioarea); + + spi_master_put(hw->master); + return 0; +} + +static struct platform_driver nuc900_spi_driver = { + .probe = nuc900_spi_probe, + .remove = __devexit_p(nuc900_spi_remove), + .driver = { + .name = "nuc900-spi", + .owner = THIS_MODULE, + }, +}; + +static int __init nuc900_spi_init(void) +{ + return platform_driver_register(&nuc900_spi_driver); +} + +static void __exit nuc900_spi_exit(void) +{ + platform_driver_unregister(&nuc900_spi_driver); +} + +module_init(nuc900_spi_init); +module_exit(nuc900_spi_exit); + +MODULE_AUTHOR("Wan ZongShun <mcuos.com@gmail.com>"); +MODULE_DESCRIPTION("nuc900 spi driver!"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:nuc900-spi"); |