On Sun, Feb 16, 2014 at 10:03:01PM +0800, Shawn Guo wrote:
> For imx50-weim and imx6q-weim type of devices, 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 such type of devices, 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.
>
> Signed-off-by: Shawn Guo <shawn.guo@xxxxxxxxxx>
> ---
> Changes since v3:
> - Add DT property fsl,weim-cs-gpr back, so that the support can work
> for more i.MX SoCs than just i.MX6Q.
>
> Documentation/devicetree/bindings/bus/imx-weim.txt | 27 +++++++++-
> drivers/bus/imx-weim.c | 55 ++++++++++++++++++++
> 2 files changed, 81 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/bus/imx-weim.txt b/Documentation/devicetree/bindings/bus/imx-weim.txt
> index 0fd76c4..363c970 100644
> --- a/Documentation/devicetree/bindings/bus/imx-weim.txt
> +++ b/Documentation/devicetree/bindings/bus/imx-weim.txt
> @@ -8,7 +8,12 @@ The actual devices are instantiated from the child nodes of a WEIM node.
>
> Required properties:
>
> - - compatible: Should be set to "fsl,<soc>-weim"
> + - compatible: Should contain one of the following:
> + "fsl,imx1-weim"
> + "fsl,imx27-weim"
> + "fsl,imx51-weim"
> + "fsl,imx50-weim"
> + "fsl,imx6q-weim"
> - reg: A resource specifier for the register space
> (see the example below)
> - clocks: the clock, see the example below.
> @@ -19,6 +24,26 @@ Required properties:
>
> <cs-number> 0 <physical address of mapping> <size>
>
> +Optional properties:
> +
> + - fsl,weim-cs-gpr: For "fsl,imx50-weim" and "fsl,imx6q-weim" type of
> + devices, it should be the phandle to the system General
> + Purpose Register controller that contains WEIM CS GPR
> + register, e.g. IOMUXC_GPR1 on i.MX6Q. IOMUXC_GPR1[11:0]
> + should be set up as one of the following 4 possible
> + values depending on the CS space configuration.
> +
> + IOMUXC_GPR1[11:0] CS0 CS1 CS2 CS3
> + ---------------------------------------------
> + 05 128M 0M 0M 0M
> + 033 64M 64M 0M 0M
> + 0113 64M 32M 32M 0M
> + 01111 32M 32M 32M 32M
> +
> + In case that the property is absent, the reset value or
> + what bootloader sets up in IOMUXC_GPR1[11:0] will be
> + used.
> +
> Timing property for child nodes. It is mandatory, not optional.
>
> - fsl,weim-cs-timing: The timing array, contains timing values for the
Could you also add the following line to the example in the same file :
fsl,weim-cs-gpr = <&gpr>;
It took me some time to figure it out :)
> diff --git a/drivers/bus/imx-weim.c b/drivers/bus/imx-weim.c
> index 3ef58c8..35e9529 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 +59,55 @@ static const struct of_device_id weim_id_table[] = {
> };
> MODULE_DEVICE_TABLE(of, weim_id_table);
>
> +static int __init imx_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) */
> + 01111, /* CS0(64M) CS1(32M) CS2(32M) CS3(0M) */
CS0(32M) CS3(32M)
> + };
> + u32 gprval = 0;
> + u32 val;
> + int cs = 0;
> + int i = 0;
> +
> + gpr = syscon_regmap_lookup_by_phandle(np, "fsl,weim-cs-gpr");
> + if (IS_ERR(gpr)) {
> + dev_dbg(&pdev->dev, "failed to find weim-cs-gpr\n");
> + return 0;
> + }
> +
> + of_property_for_each_u32(np, "ranges", prop, p, val) {
> + if (i % 4 == 0) {
> + cs = val;
> + } else if (i % 4 == 3 && val) {
> + val = (val / SZ_32M) | 1;
> + gprval |= val << cs * 3;
> + }
> + i++;
> + }
> +
> + 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 +144,9 @@ static int __init weim_parse_dt(struct platform_device *pdev,
> struct device_node *child;
> int ret;
>
> + if (devtype == &imx50_weim_devtype)
> + imx_weim_gpr_setup(pdev);
> +
> for_each_child_of_node(pdev->dev.of_node, child) {
> if (!child->name)
> continue;
> --
> 1.7.9.5
>
--
Philippe De Muyter +32 2 6101532 Macq SA rue de l'Aeronef 2 B-1140 Bruxelles
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