Permalink
Switch branches/tags
Nothing to show
Find file
Fetching contributors…
Cannot retrieve contributors at this time
506 lines (390 sloc) 10.2 KB
/* 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/slab.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_bitbang_stop(&hw->bitbang);
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");