Hello Simon,
Simon Glass wrote:
From: Yen Lin yelin@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: sjg@chromium.org modified for upstream)
Signed-off-by: Simon Glass sjg@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