[PATCH v4 2/3] bus: imx-weim: support multiple address ranges per child node

[Sven Van Asbroeck]

Ensure that timing values for the child node are applied to
all chip selects in the child's address ranges.

Note that this does not support multiple timing settings per
child; this can be added in the future if required.

Example:
&weim {
        acme@0 {
                compatible = "acme,whatever";
                reg = <0 0 0x100>, <0 0x400000 0x800>,
                                <1 0x400000 0x800>;
                fsl,weim-cs-timing = <0x024400b1 0x00001010 0x20081100
                                0x00000000 0xa0000240 0x00000000>;
        };
};

Signed-off-by: Sven Van Asbroeck <thesve...@googlemail.com>
---
 drivers/bus/imx-weim.c | 35 +++++++++++++++++++++++++----------
 1 file changed, 25 insertions(+), 10 deletions(-)

diff --git a/drivers/bus/imx-weim.c b/drivers/bus/imx-weim.c
index d84996a4528e..1a0e0277a404 100644
--- a/drivers/bus/imx-weim.c
+++ b/drivers/bus/imx-weim.c
@@ -46,6 +46,7 @@ static const struct imx_weim_devtype imx51_weim_devtype = {
 };
 
 #define MAX_CS_REGS_COUNT      6
+#define OF_REG_SIZE            3
 
 static const struct of_device_id weim_id_table[] = {
        /* i.MX1/21 */
@@ -116,26 +117,40 @@ static int __init weim_timing_setup(struct device_node 
*np, void __iomem *base,
 {
        u32 cs_idx, value[MAX_CS_REGS_COUNT];
        int i, ret;
+       int reg_idx, num_regs;
 
        if (WARN_ON(devtype->cs_regs_count > MAX_CS_REGS_COUNT))
                return -EINVAL;
 
-       /* get the CS index from this child node's "reg" property. */
-       ret = of_property_read_u32(np, "reg", &cs_idx);
+       ret = of_property_read_u32_array(np, "fsl,weim-cs-timing",
+                                        value, devtype->cs_regs_count);
        if (ret)
                return ret;
 
-       if (cs_idx >= devtype->cs_count)
+       /*
+        * the child node's "reg" property may contain multiple address ranges,
+        * extract the chip select for each.
+        */
+       num_regs = of_property_count_elems_of_size(np, "reg", OF_REG_SIZE);
+       if (num_regs < 0)
+               return num_regs;
+       if (!num_regs)
                return -EINVAL;
+       for (reg_idx = 0; reg_idx < num_regs; reg_idx++) {
+               /* get the CS index from this child node's "reg" property. */
+               ret = of_property_read_u32_index(np, "reg",
+                                       reg_idx * OF_REG_SIZE, &cs_idx);
+               if (ret)
+                       break;
 
-       ret = of_property_read_u32_array(np, "fsl,weim-cs-timing",
-                                        value, devtype->cs_regs_count);
-       if (ret)
-               return ret;
+               if (cs_idx >= devtype->cs_count)
+                       return -EINVAL;
 
-       /* set the timing for WEIM */
-       for (i = 0; i < devtype->cs_regs_count; i++)
-               writel(value[i], base + cs_idx * devtype->cs_stride + i * 4);
+               /* set the timing for WEIM */
+               for (i = 0; i < devtype->cs_regs_count; i++)
+                       writel(value[i],
+                               base + cs_idx * devtype->cs_stride + i * 4);
+       }
 
        return 0;
 }
-- 
2.17.1