Hi Shawn,
On Thu, Feb 13, 2014 at 08:59:02PM +0800, Shawn Guo wrote:
> For imx6q-weim type of device, there might a WEIM CS space configuration
> register in General Purpose Register controller, e.g. IOMUXC_GPR1 on
> i.MX6Q.
>
> Depending on which configuration of the following 4 is chosen for given
> system, IOMUXC_GPR1[11:0] should be set up as 05, 033, 0113 or 01111
> correspondingly.
>
> CS0(128M) CS1(0M) CS2(0M) CS3(0M)
> CS0(64M) CS1(64M) CS2(0M) CS3(0M)
> CS0(64M) CS1(32M) CS2(32M) CS3(0M)
> CS0(32M) CS1(32M) CS2(32M) CS3(32M)
>
> The patch creates a function for imx6q-weim type of device, which scans
> 'ranges' property of WEIM node and build the GPR value incrementally.
> Thus the WEIM CS GPR can be set up automatically at boot time.
Please add that text to Documentation/devicetree/bindings/bus/imx-weim.txt.
>
> Signed-off-by: Shawn Guo <shawn.guo@xxxxxxxxxx>
> ---
> Changes since v1:
> - Drop device tree property fsl,weim-cs-gpr
> - Use octal value for IOMUXC_GPR1[11:0] bit field
> - Use of_property_for_each_u32() to build gprval incrementally
>
> drivers/bus/imx-weim.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 59 insertions(+)
>
> diff --git a/drivers/bus/imx-weim.c b/drivers/bus/imx-weim.c
> index 3ef58c8..a120c93 100644
> --- a/drivers/bus/imx-weim.c
> +++ b/drivers/bus/imx-weim.c
> @@ -11,6 +11,9 @@
> #include <linux/clk.h>
> #include <linux/io.h>
> #include <linux/of_device.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
> +#include <linux/regmap.h>
>
> struct imx_weim_devtype {
> unsigned int cs_count;
> @@ -56,6 +59,59 @@ static const struct of_device_id weim_id_table[] = {
> };
> MODULE_DEVICE_TABLE(of, weim_id_table);
>
> +static int __init imx6q_weim_gpr_setup(struct platform_device *pdev)
> +{
> + struct device_node *np = pdev->dev.of_node;
> + struct property *prop;
> + const __be32 *p;
> + struct regmap *gpr;
> + u32 gprvals[4] = {
> + 05, /* CS0(128M) CS1(0M) CS2(0M) CS3(0M) */
> + 033, /* CS0(64M) CS1(64M) CS2(0M) CS3(0M) */
> + 0113, /* CS0(64M) CS1(32M) CS2(32M) CS3(0M) */
> + 0111, /* CS0(64M) CS1(32M) CS2(32M) CS3(0M) */
01111, /* CS0(32M) CS1(32M) CS2(32M) CS3(32M) */
> + };
> + u32 gprval = 0;
> + u32 val;
> + int len;
> + int cs = 0;
> + int i = 0;
> +
> + gpr = syscon_regmap_lookup_by_compatible("fsl,imx6q-iomuxc-gpr");
> + if (IS_ERR(gpr)) {
> + dev_err(&pdev->dev, "failed to find fsl,imx6q-iomuxc-gpr\n");
> + return -ENOENT;
> + }
> +
> + prop = of_find_property(np, "ranges", &len);
> + if (prop == NULL)
> + return -ENOENT;
> + if (len % (sizeof(u32) * 4))
> + return -EINVAL;
> +
> + of_property_for_each_u32(np, "ranges", prop, p, val) {
> + if (i % 4 == 0) {
> + cs = val;
> + } else if (i % 4 == 3 && val) {
> + val /= SZ_64M;
> + val = (val << 1) | 1;
or
val = (val / SZ_32M) | 1;
> + gprval |= val << cs * 3;
> + }
> + i++;
> + }
You may replace the tests above (from "prop = of_find_property" to "EINVAL;")
by :
if (i == 0 || (i % 4))
goto err;
> +
> + for (i = 0; i < ARRAY_SIZE(gprvals); i++) {
> + if (gprval == gprvals[i]) {
> + /* Found it. Set up IOMUXC_GPR1[11:0] with it. */
> + regmap_update_bits(gpr, IOMUXC_GPR1, 0xfff, gprval);
> + return 0;
> + }
> + }
> +
err:
> + dev_err(&pdev->dev, "Invalid 'ranges' configuration\n");
> + return -EINVAL;
> +}
> +
> /* Parse and set the timing for this device. */
> static int __init weim_timing_setup(struct device_node *np, void __iomem *base,
> const struct imx_weim_devtype *devtype)
> @@ -92,6 +148,9 @@ static int __init weim_parse_dt(struct platform_device *pdev,
> struct device_node *child;
> int ret;
>
> + if (of_device_is_compatible(pdev->dev.of_node, "fsl,imx6q-weim"))
> + imx6q_weim_gpr_setup(pdev);
> +
> for_each_child_of_node(pdev->dev.of_node, child) {
> if (!child->name)
> continue;
> --
> 1.7.9.5
>
I have tested this v2 patch, and, except for the typo (0111 instead of 01111),
it works perfectly.
Thanks
Philippe
--
Philippe De Muyter +32 2 6101532 Macq SA rue de l'Aeronef 2 B-1140 Bruxelles
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