[U-Boot] [PATCH v4 5/9] tegra: i2c: Add I2C driver

[Mike Frysinger]

On Wednesday 29 February 2012 12:31:25 Simon Glass wrote:
> --- /dev/null
> +++ b/arch/arm/include/asm/arch-tegra2/tegra_i2c.h
>
> +/* Convert i2c slave address to be put on bus  */
> +#define I2C_ADDR_ON_BUS(chip)		(chip << 1)

i'm not sure the desc here is correct ... it's at least a little bit 
misleading.  addresses are 7bits, and the 8th bit is for telling the device to 
read/write.  since it only gets used in two places, might be better to inline 
the bit shift there ?  hard to say.

> --- /dev/null
> +++ b/drivers/i2c/tegra_i2c.c
>
> + * Copyright (c) 2011 The Chromium OS Authors. All rights reserved.

guess you need to -2012 that now ;)

> +#include <common.h>
> +#include <asm/io.h>
> +#include <asm/arch/clk_rst.h>
> +#include <asm/arch/clock.h>
> +#include <asm/arch/funcmux.h>
> +#include <asm/arch/gpio.h>
> +#include <asm/arch/pinmux.h>
> +#include <asm/arch/tegra_i2c.h>
> +#include <fdtdec.h>

needs to include i2c.h to make sure your local defs stay inline with the 
prototypes everyone else is using.  also, asm/* generally should come last (so 
after ftdec.h).

> +static int send_recv_packets(
> +	struct i2c_bus *i2c_bus,
> +	struct i2c_trans_info *trans)
> +{
> +	struct i2c_control *control = i2c_bus->control;
> +	u32 int_status;
> +	u32 words;
> +	u8 *dptr;
> +	u32 local;
> +	uchar last_bytes;
> +	int error = 0;
> +	int is_write = trans->flags & I2C_IS_WRITE;
> +
> +	/* clear status from previous transaction, XFER_COMPLETE, NOACK, etc. */
> +	int_status = readl(&control->int_status);
> +	writel(int_status, &control->int_status);
> +
> +	send_packet_headers(i2c_bus, trans, 1);
> +
> +	words = DIV_ROUND_UP(trans->num_bytes, 4);
> +	last_bytes = trans->num_bytes & 3;
> +	dptr = trans->buf;
> +
> +	while (words) {
> +		if (is_write) {
> +			/* deal with word alignment */
> +			if ((unsigned)dptr & 3) {
> +				memcpy(&local, dptr, sizeof(u32));
> +				writel(local, &control->tx_fifo);
> +				debug("pkt data sent (0x%x)\n", local);
> +			} else {
> +				writel(*(u32 *)dptr, &control->tx_fifo);
> +				debug("pkt data sent (0x%x)\n", *(u32 *)dptr);

generally inlining these types of bitsized casts are discouraged ...
-mike
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 836 bytes
Desc: This is a digitally signed message part.
URL: <http://lists.denx.de/pipermail/u-boot/attachments/20120301/93d666c6/attachment.pgp>