[PATCH 1/2] bus: imx-weim: optionally enable burst clock mode

[Sven Van Asbroeck]

To enable burst clock mode, add the fsl,burst-clk-enable
property to the weim bus's devicetree node.

Example:
weim: weim@21b8000 {
        compatible = "fsl,imx6q-weim";
        reg = <0x021b8000 0x4000>;
        clocks = <&clks 196>;
        #address-cells = <2>;
        #size-cells = <1>;
        ranges = <0 0 0x08000000 0x08000000>;
        fsl,weim-cs-gpr = <&gpr>;
        fsl,burst-clk-enable;

        client-device@0,0 {
                compatible = "something";
                reg = <0 0 0x02000000>;
                #address-cells = <1>;
                #size-cells = <1>;
                bank-width = <2>;
                fsl,weim-cs-timing = <0x00620081 0x00000001 0x1c022000
                                0x0000c000 0x1404a38e 0x00000000>;
        };
};

Signed-off-by: Sven Van Asbroeck <thesve...@gmail.com>
---
 drivers/bus/imx-weim.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/bus/imx-weim.c b/drivers/bus/imx-weim.c
index db74334ca5ef..cb7d5504a22a 100644
--- a/drivers/bus/imx-weim.c
+++ b/drivers/bus/imx-weim.c
@@ -19,6 +19,8 @@ struct imx_weim_devtype {
        unsigned int    cs_count;
        unsigned int    cs_regs_count;
        unsigned int    cs_stride;
+       unsigned int    wcr_offset;
+       unsigned int    wcr_bcm;
 };
 
 static const struct imx_weim_devtype imx1_weim_devtype = {
@@ -37,6 +39,8 @@ static const struct imx_weim_devtype imx50_weim_devtype = {
        .cs_count       = 4,
        .cs_regs_count  = 6,
        .cs_stride      = 0x18,
+       .wcr_offset     = 0x90,
+       .wcr_bcm        = BIT(0),
 };
 
 static const struct imx_weim_devtype imx51_weim_devtype = {
@@ -192,6 +196,7 @@ static int __init weim_parse_dt(struct platform_device 
*pdev,
        struct device_node *child;
        int ret, have_child = 0;
        struct cs_timing_state ts = {};
+       u32 reg;
 
        if (devtype == &imx50_weim_devtype) {
                ret = imx_weim_gpr_setup(pdev);
@@ -199,6 +204,17 @@ static int __init weim_parse_dt(struct platform_device 
*pdev,
                        return ret;
        }
 
+       if (of_property_read_bool(pdev->dev.of_node, "fsl,burst-clk-enable")) {
+               if (devtype->wcr_bcm) {
+                       reg = readl(base + devtype->wcr_offset);
+                       writel(reg | devtype->wcr_bcm,
+                               base + devtype->wcr_offset);
+               } else {
+                       dev_err(&pdev->dev, "burst clk mode not supported.\n");
+                       return -EINVAL;
+               }
+       }
+
        for_each_available_child_of_node(pdev->dev.of_node, child) {
                ret = weim_timing_setup(&pdev->dev, child, base, devtype, &ts);
                if (ret)
-- 
2.17.1