On Tue, 25 Mar 2008 19:55:59 +0900
Paul Mundt <[EMAIL PROTECTED]> wrote:
> This is V3 of the SuperH Mobile I2C Controller Driver. A simple Master
> only driver for the I2C block included in processors such as sh7343,
> sh7722 and sh7723. Tested on a sh7722 MigoR using a rs5c372b rtc.
>
> +#include <asm/io.h>
please use checkpatch.
> +static unsigned char i2c_op(struct sh_mobile_i2c_data *pd,
> + int op, unsigned char data)
> +{
> + unsigned char ret = 0;
> +
> + dev_dbg(pd->dev, "op %d, data in 0x%02x\n", op, data);
> +
> + spin_lock_irq(&pd->lock);
> +
> + switch (op) {
> + case OP_START:
> + iowrite8(0x94, ICCR(pd));
> + break;
> + case OP_TX_ONLY:
> + iowrite8(data, ICDR(pd));
> + break;
> + case OP_TX_STOP:
> + iowrite8(data, ICDR(pd));
> + iowrite8(0x90, ICCR(pd));
> + iowrite8(ICIC_ALE | ICIC_TACKE, ICIC(pd));
> + break;
> + case OP_TX_TO_RX:
> + iowrite8(data, ICDR(pd));
> + iowrite8(0x81, ICCR(pd));
> + break;
> + case OP_RX_ONLY:
> + ret = ioread8(ICDR(pd));
> + break;
> + case OP_RX_STOP:
> + ret = ioread8(ICDR(pd));
> + iowrite8(0xc0, ICCR(pd));
> + break;
> + }
> +
> + spin_unlock_irq(&pd->lock);
> +
> + dev_dbg(pd->dev, "op %d, data out 0x%02x\n", op, ret);
> + return ret;
> +}
I'd be a bit concerned about reenabling interrupts...
> +static irqreturn_t sh_mobile_i2c_isr(int irq, void *dev_id)
> +{
> + struct platform_device *dev = dev_id;
> + struct sh_mobile_i2c_data *pd = platform_get_drvdata(dev);
> + struct i2c_msg *msg = pd->msg;
> + unsigned char data, sr;
> + int wakeup = 0;
> +
> + sr = ioread8(ICSR(pd));
> + pd->sr |= sr;
> +
> + dev_dbg(pd->dev, "i2c_isr 0x%02x 0x%02x %s %d %d!\n", sr, pd->sr,
> + (msg->flags & I2C_M_RD) ? "read" : "write",
> + pd->pos, msg->len);
> +
> + if (sr & (ICSR_AL | ICSR_TACK)) {
> + iowrite8(0, ICIC(pd)); /* disable interrupts */
> + wakeup = 1;
> + goto do_wakeup;
> + }
> +
> + if (pd->pos == msg->len) {
> + i2c_op(pd, OP_RX_ONLY, 0);
from the interrupt handler...
> +static int sh_mobile_i2c_hook_irqs(struct platform_device *dev, int hook)
> +{
> + struct resource *res;
> + int ret = -ENXIO;
> + int q, m;
> + int k = 0;
> + int n = 0;
> +
> + while ((res = platform_get_resource(dev, IORESOURCE_IRQ, k))) {
> + for (n = res->start; hook && n <= res->end; n++) {
> + if (request_irq(n, sh_mobile_i2c_isr, 0,
> + dev->dev.bus_id, dev))
even though it isn't using IRQF_DISABLED here,
: int request_irq(unsigned int irq, irq_handler_t handler,
: unsigned long irqflags, const char *devname, void *dev_id)
: {
: struct irqaction *action;
: int retval;
:
: #ifdef CONFIG_LOCKDEP
: /*
: * Lockdep wants atomic interrupt handlers:
: */
: irqflags |= IRQF_DISABLED;
: #endif
it will do so if lockdep is supported.
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