Thanks Shawn.
On Tue, Feb 11, 2014 at 10:50:11AM +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 0x5, 0x1b, 0x4b or 0x249
As the bits are actually grouped by 3, one could write:
... 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 table in the driver for above configurations, and
> detects which one is being used for the booting system by looking at
> 'ranges' property of WEIM node. Thus the WEIM CS GPR can be set up
> automatically at boot time.
>
> Signed-off-by: Shawn Guo <shawn.guo@xxxxxxxxxx>
> ---
> Documentation/devicetree/bindings/bus/imx-weim.txt | 6 ++
> drivers/bus/imx-weim.c | 83 ++++++++++++++++++++
> 2 files changed, 89 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/bus/imx-weim.txt b/Documentation/devicetree/bindings/bus/imx-weim.txt
> index 0fd76c4..d114460f 100644
> --- a/Documentation/devicetree/bindings/bus/imx-weim.txt
> +++ b/Documentation/devicetree/bindings/bus/imx-weim.txt
> @@ -19,6 +19,12 @@ Required properties:
>
> <cs-number> 0 <physical address of mapping> <size>
>
> +Optional properties:
> +
> + - fsl,weim-cs-gpr: Should be the phandle to the General Purpose Register
> + controller that contains WEIM CS GPR register, e.g.
> + IOMUXC_GPR1 on i.MX6Q.
> +
Why require that new property ? It makes things harder to use.
And you could add the body of your commit log here.
> Timing property for child nodes. It is mandatory, not optional.
>
> - fsl,weim-cs-timing: The timing array, contains timing values for the
> diff --git a/drivers/bus/imx-weim.c b/drivers/bus/imx-weim.c
> index 3ef58c8..9c8a522 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 +59,83 @@ static const struct of_device_id weim_id_table[] = {
> };
> MODULE_DEVICE_TABLE(of, weim_id_table);
>
> +struct imx6q_weim_gpr {
> + u32 cssize[4];
> + u32 gprval;
> +};
> +
> +static const struct imx6q_weim_gpr imx6q_weim_gpr_data[] __initconst = {
> + {
> + /* CS0(128M) CS1(0M) CS2(0M) CS3(0M) */
> + .cssize = { 128, 0, 0, 0 },
> + .gprval = 0x5,
05
> + }, {
> + /* CS0(64M) CS1(64M) CS2(0M) CS3(0M) */
> + .cssize = { 64, 64, 0, 0 },
> + .gprval = 0x1b,
033
> + }, {
> + /* CS0(64M) CS1(32M) CS2(32M) CS3(0M) */
> + .cssize = { 64, 32, 32, 0 },
> + .gprval = 0x4b,
0113
> + }, {
> + /* CS0(64M) CS1(32M) CS2(32M) CS3(0M) */
/* CS0(32M) CS1(32M) CS2(32M) CS3(32M) */
> + .cssize = { 32, 32, 32, 32 },
> + .gprval = 0x249,
01111
> + },
> +};
> +
> +static int __init imx6q_weim_gpr_setup(struct platform_device *pdev)
> +{
> + struct device_node *np = pdev->dev.of_node;
> + const struct property *prop;
> + struct regmap *gpr;
> + u32 cssize[4] = { 0, 0, 0, 0 };
> + int len;
> + int ret;
> + int i;
> +
> + gpr = syscon_regmap_lookup_by_phandle(np, "fsl,weim-cs-gpr");
gpr = syscon_regmap_lookup_by_compatible("fsl,imx6q-iomuxc-gpr");
> + if (IS_ERR(gpr)) {
> + dev_dbg(&pdev->dev, "No weim-cs-gpr to set up\n");
> + return 0;
> + }
> +
> + prop = of_find_property(np, "ranges", &len);
> + if (prop == NULL)
> + return -ENOENT;
> + if (len % (sizeof(u32) * 4))
> + return -EINVAL;
> +
> + for (i = 0; i < len / (sizeof(u32) * 4); i++) {
> + int cs;
> + /* read cs index */
> + ret = of_property_read_u32_index(np, "ranges", i * 4, &cs);
> + if (ret)
> + return ret;
> + /* read cs size */
> + ret = of_property_read_u32_index(np, "ranges", i * 4 + 3,
> + &cssize[cs]);
> + if (ret)
> + return ret;
> + /* turn to MB */
> + cssize[cs] >>= 20;
> + }
> +
> + for (i = 0; i < ARRAY_SIZE(imx6q_weim_gpr_data); i++) {
> + ret = memcmp(cssize, imx6q_weim_gpr_data[i].cssize,
> + sizeof(cssize));
> + if (ret == 0) {
> + /* Find it. Set up IOMUXC_GPR1[11:0] with the gprval. */
Found it
> + regmap_update_bits(gpr, IOMUXC_GPR1, 0xfff,
> + imx6q_weim_gpr_data[i].gprval);
> + return 0;
> + }
> + }
> +
> + 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 +172,9 @@ 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
>
Now the most important : it works. I have tested it successfully for the
4 combinations.
Code could probably be made shorter by using 'of_prop_next_u32' and building
the gprval incrementally, then checking it against the four possible values,
though.
But, again, thanks, Shawn
--
Philippe De Muyter +32 2 6101532 Macq SA rue de l'Aeronef 2 B-1140 Bruxelles
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