drivers/i2c/busses/i2c-highlander.c

Source file repositories/reference/linux-study-clean/drivers/i2c/busses/i2c-highlander.c

File Facts

System
Linux kernel
Corpus path
drivers/i2c/busses/i2c-highlander.c
Extension
.c
Size
10850 bytes
Lines
477
Domain
Driver Families
Bucket
drivers/i2c
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct highlander_i2c_dev {
	struct device		*dev;
	void __iomem		*base;
	struct i2c_adapter	adapter;
	struct completion	cmd_complete;
	unsigned long		last_read_time;
	int			irq;
	u8			*buf;
	size_t			buf_len;
};

static bool iic_force_poll, iic_force_normal;
static int iic_timeout = 1000, iic_read_delay;

static inline void highlander_i2c_irq_enable(struct highlander_i2c_dev *dev)
{
	iowrite16(ioread16(dev->base + SMCR) | SMCR_IEIC, dev->base + SMCR);
}

static inline void highlander_i2c_irq_disable(struct highlander_i2c_dev *dev)
{
	iowrite16(ioread16(dev->base + SMCR) & ~SMCR_IEIC, dev->base + SMCR);
}

static inline void highlander_i2c_start(struct highlander_i2c_dev *dev)
{
	iowrite16(ioread16(dev->base + SMCR) | SMCR_START, dev->base + SMCR);
}

static inline void highlander_i2c_done(struct highlander_i2c_dev *dev)
{
	iowrite16(ioread16(dev->base + SMCR) | SMCR_IRIC, dev->base + SMCR);
}

static void highlander_i2c_setup(struct highlander_i2c_dev *dev)
{
	u16 smmr;

	smmr = ioread16(dev->base + SMMR);
	smmr |= SMMR_TMMD;

	if (iic_force_normal)
		smmr &= ~SMMR_SP;
	else
		smmr |= SMMR_SP;

	iowrite16(smmr, dev->base + SMMR);
}

static void smbus_write_data(u8 *src, u16 *dst, int len)
{
	for (; len > 1; len -= 2) {
		*dst++ = be16_to_cpup((__be16 *)src);
		src += 2;
	}

	if (len)
		*dst = *src << 8;
}

static void smbus_read_data(u16 *src, u8 *dst, int len)
{
	for (; len > 1; len -= 2) {
		*(__be16 *)dst = cpu_to_be16p(src++);
		dst += 2;
	}

	if (len)
		*dst = *src >> 8;
}

static void highlander_i2c_command(struct highlander_i2c_dev *dev,
				   u8 command, int len)
{
	unsigned int i;
	u16 cmd = (command << 8) | command;

	for (i = 0; i < len; i += 2) {
		if (len - i == 1)
			cmd = command << 8;
		iowrite16(cmd, dev->base + SMSADR + i);
		dev_dbg(dev->dev, "command data[%x] 0x%04x\n", i/2, cmd);
	}
}

static int highlander_i2c_wait_for_bbsy(struct highlander_i2c_dev *dev)
{
	unsigned long timeout;

	timeout = jiffies + msecs_to_jiffies(iic_timeout);

Annotation

Implementation Notes