Fwd: [PATCH 1/3] i2c: Add Device Tree support to the Nomadik I2C driver
From: Srinidhi Kasagar <hidden>
Date: 2012-06-15 11:51:07
Also in:
linux-i2c, lkml
[...]
quoted hunk
From: Lee Jones <redacted> Date: Tue, 17 Apr 2012 16:04:13 +0100 Subject: [PATCH 1/1] i2c: Add Device Tree support to the Nomadik I2C driver Here we apply the bindings required for successful Device Tree probing of the i2c-nomadik driver. We also apply a fall-back configuration in case either one is not provided, or a required element is missing from the one supplied. Cc: linux-i2c at vger.kernel.org Signed-off-by: Lee Jones <redacted> --- drivers/i2c/busses/i2c-nomadik.c | 82 +++++++++++++++++++++++++++++++++++++- 1 file changed, 80 insertions(+), 2 deletions(-)diff --git a/drivers/i2c/busses/i2c-nomadik.c b/drivers/i2c/busses/i2c-nomadik.c index a92440d..58e8114 100644 --- a/drivers/i2c/busses/i2c-nomadik.c +++ b/drivers/i2c/busses/i2c-nomadik.c@@ -23,6 +23,7 @@ #include <linux/io.h> #include <linux/regulator/consumer.h> #include <linux/pm_runtime.h> +#include <linux/of.h> #include <plat/i2c.h>@@ -899,15 +900,86 @@ static const struct i2c_algorithm nmk_i2c_algo = { .functionality = nmk_i2c_functionality }; +static struct nmk_i2c_controller u8500_i2c = { + /* + * Slave data setup time; 250ns, 100ns, and 10ns, which + * is 14, 6 and 2 respectively for a 48Mhz i2c clock. + */ + .slsu = 0xe, + .tft = 1, /* Tx FIFO threshold */ + .rft = 8, /* Rx FIFO threshold */ + .clk_freq = 100000, /* std. mode operation */ + .timeout = 200, /* Slave response timeout(ms) */ + .sm = I2C_FREQ_MODE_FAST,
How is this possible? you are setting clk_freq as 100kb/s and mode as fast mode which is supposed to be 400kb/s.
+};
+
+static int __devinit
+nmk_i2c_of_probe(struct device_node *np, struct nmk_i2c_controller *pdata)
+{
+ of_property_read_u32(np, "clock-frequency", (u32*)&pdata->clk_freq);
+ if (!pdata->clk_freq) {
+ pr_warn("%s: Clock frequency not found\n", np->full_name);
+ return -EINVAL;
+ }
+
+ of_property_read_u32(np, "stericsson,slsu", (u32*)&pdata->slsu);
+ if (!pdata->slsu) {
+ pr_warn("%s: Data line delay not found\n", np->full_name);
+ return -EINVAL;
+ }
+
+ of_property_read_u32(np, "stericsson,tft", (u32*)&pdata->tft);
+ if (!pdata->tft) {
+ pr_warn("%s: Tx FIFO threshold not found\n", np->full_name);
+ return -EINVAL;
+ }
+
+ of_property_read_u32(np, "stericsson,rft", (u32*)&pdata->rft);
+ if (!pdata->rft) {
+ pr_warn("%s: Rx FIFO threshold not found\n", np->full_name);
+ return -EINVAL;
+ }
+
+ of_property_read_u32(np, "stericsson,timeout", (u32*)&pdata->timeout);
+ if (!pdata->timeout) {
+ pr_warn("%s: Timeout not found\n", np->full_name);
+ return -EINVAL;
+ }
+
+ if (of_get_property(np, "stericsson,i2c_freq_mode_fast", NULL))
+ pdata->sm = I2C_FREQ_MODE_FAST;
+ else
+ pdata->sm = I2C_FREQ_MODE_STANDARD;The controller has more modes like fast mode plus and high speed mode. You can't make assumptions like this.
+
+ return 0;
+}
+
static int __devinit nmk_i2c_probe(struct platform_device *pdev)
{
int ret = 0;
struct resource *res;
- struct nmk_i2c_controller *pdata =
- pdev->dev.platform_data;
+ struct nmk_i2c_controller *pdata = pdev->dev.platform_data;
+ struct device_node *np = pdev->dev.of_node;
struct nmk_i2c_dev *dev;
struct i2c_adapter *adap;
+ if (np) {
+ if (!pdata) {
+ pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+ if (!pdata) {
+ ret = -ENOMEM;
+ goto err_no_mem;
+ }
+ }
+ ret = nmk_i2c_of_probe(np, pdata);
+ if (ret)
+ kfree(pdata);
+ }
+
+ if (!pdata)
+ /* No i2c configuration found, using the default. */
+ pdata = &u8500_i2c;There are redundant fallback configurations exists in the driver. You might need to remove those, if you want to fallback here.
quoted hunk
+ dev = kzalloc(sizeof(struct nmk_i2c_dev), GFP_KERNEL); if (!dev) { dev_err(&pdev->dev, "cannot allocate memory\n");@@ -1038,11 +1110,17 @@ static int __devexit nmk_i2c_remove(struct platform_device *pdev) return 0; } +static const struct of_device_id nmk_gpio_match[] = { + { .compatible = "st,nomadik-i2c", }, + {}, +}; + static struct platform_driver nmk_i2c_driver = { .driver = { .owner = THIS_MODULE, .name = DRIVER_NAME, .pm = &nmk_i2c_pm, + .of_match_table = nmk_gpio_match, }, .probe = nmk_i2c_probe, .remove = __devexit_p(nmk_i2c_remove), --1.7.9.5
/srinidhi