Hello Simon,
Simon Glass wrote:
> From: Yen Lin <ye...@nvidia.com>
>
> Add basic i2c driver for Tegra2 with 8- and 16-bit address support.
> The driver requires CONFIG_OF_CONTROL to obtain its configuration
> from the device tree.
>
> (Simon Glass: s...@chromium.org modified for upstream)
>
> Signed-off-by: Simon Glass <s...@chromium.org>
> ---
> Changes in v2:
> - Use DIV_ROUND_UP() instead of a home-grown macro
> - Tidy comment style
> - Change i2c array to static
> - Adjust definitions to fit new peripheral clock bindings
> - Remove i2c configuring using CONFIG (use fdt instead)
Why? Ah found it ... Hmm.. why we don't need the non OF
case?
> - Make i2c/dvc decision come from fdt
> - Use new fdtdec alias decode function
> - Simplify code in i2c_addr_ok()
> - Return an error if an unavailable i2c bus is selected
>
> arch/arm/include/asm/arch-tegra2/tegra2_i2c.h | 160 +++++++
> drivers/i2c/Makefile | 1 +
> drivers/i2c/tegra2_i2c.c | 551
> +++++++++++++++++++++++++
> include/fdtdec.h | 2 +
> lib/fdtdec.c | 2 +
> 5 files changed, 716 insertions(+), 0 deletions(-)
> create mode 100644 arch/arm/include/asm/arch-tegra2/tegra2_i2c.h
> create mode 100644 drivers/i2c/tegra2_i2c.c
[...]
> diff --git a/drivers/i2c/tegra2_i2c.c b/drivers/i2c/tegra2_i2c.c
> new file mode 100644
> index 0000000..a7db714
> --- /dev/null
> +++ b/drivers/i2c/tegra2_i2c.c
> @@ -0,0 +1,551 @@
[...]
> +static void i2c_init_controller(struct i2c_bus *i2c_bus)
> +{
> + /* TODO: Fix bug which makes us need to do this */
> + clock_start_periph_pll(i2c_bus->periph_id, CLOCK_ID_OSC,
> + i2c_bus->speed * (8 * 2 - 1));
Can you use here some defines?
What is (8 * 2 - 1) ?
> +#ifndef CONFIG_OF_CONTROL
> +#error "Please enable device tree support to use this driver"
> +#endif
Hmm.. see above question. Ok, if somebody need want to use this
driver without CONFIG_OF_CONTROL it must be added ...
> +/*
> + * Process a list of nodes, adding them to our list of I2C ports.
> + *
> + * @param blob fdt blob
> + * @param node_list list of nodes to process (any <=0 are ignored)
> + * @param count number of nodes to process
> + * @param is_dvc 1 if these are DVC ports, 0 if standard I2C
> + * @return 0 if ok, -1 on error
> + */
> +static int process_nodes(const void *blob, int node_list[], int count,
> + int is_dvc)
> +{
> + struct i2c_bus *i2c_bus;
> + int i;
> +
> + /* build the i2c_controllers[] for each controller */
> + for (i = 0; i < count; i++) {
> + int node = node_list[i];
> +
> + if (node <= 0)
> + continue;
> +
> + i2c_bus = &i2c_controllers[i];
> + i2c_bus->id = i;
> +
> + if (i2c_get_config(blob, node, i2c_bus)) {
> + printf("i2c_init_board: failed to decode bus %d\n", i);
> + return -1;
> + }
> +
> + i2c_bus->is_dvc = is_dvc;
> + if (is_dvc) {
> + i2c_bus->control =
> + &((struct dvc_ctlr *)i2c_bus->regs)->control;
> + } else {
> + i2c_bus->control = &i2c_bus->regs->control;
> + }
> + debug("%s: controller bus %d at %p, periph_id %d, speed %d: ",
> + is_dvc ? "dvc" : "i2c", i, i2c_bus->regs,
> + i2c_bus->periph_id, i2c_bus->speed);
> + i2c_init_controller(i2c_bus);
> + debug("ok\n");
> + i2c_bus->inited = 1;
> +
> + /* Mark position as used */
> + node_list[i] = -1;
> + }
> +
> + return 0;
> +}
> +
> +int i2c_init_board(void)
> +{
> + int node_list[CONFIG_SYS_MAX_I2C_BUS];
> + const void *blob = gd->fdt_blob;
> + int count;
> +
> + /* First get the normal i2c ports */
> + count = fdtdec_find_aliases_for_id(blob, "i2c",
> + COMPAT_NVIDIA_TEGRA20_I2C, node_list,
> + CONFIG_SYS_MAX_I2C_BUS);
> + if (process_nodes(blob, node_list, count, 0))
> + return -1;
> +
> + /* Now look for dvc ports */
> + count = fdtdec_add_aliases_for_id(blob, "i2c",
> + COMPAT_NVIDIA_TEGRA20_DVC, node_list,
> + CONFIG_SYS_MAX_I2C_BUS);
> + if (process_nodes(blob, node_list, count, 1))
> + return -1;
> +
> + return 0;
> +}
> +
> +void i2c_init(int speed, int slaveaddr)
> +{
> + debug("i2c_init(speed=%u, slaveaddr=0x%x)\n", speed, slaveaddr);
> +}
Hmm... i2c_init is called to init the i2c subsystem ... you do nothing
here ... and use i2c_init_board for init the i2c bus, right?
But i2c_init_board is not called from the driver ... ah, you do this
in board code ... Ok ...
I think, you do this, because i2c_init is called very early, and
so processing fdt is slow?
[...]
bye,
Heiko
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