--- /dev/null
+/* 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");
projects / karo-tx-linux.git / commitdiff