[PATCH v2 1/2] bus: imx-weim: support multiple address ranges per child node

From: thesven73
Date: Fri Nov 30 2018 - 15:56:34 EST


From: Sven Van Asbroeck <TheSven73@xxxxxxxxxxxxxx>

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@0,0 {
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 <TheSven73@xxxxxxxxxxxxxx>
---
drivers/bus/imx-weim.c | 36 +++++++++++++++++++++++++-----------
1 file changed, 25 insertions(+), 11 deletions(-)

diff --git a/drivers/bus/imx-weim.c b/drivers/bus/imx-weim.c
index f01308172de9..24f22285395d 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 */
@@ -115,27 +116,40 @@ static int __init weim_timing_setup(struct device_node *np, void __iomem *base,
const struct imx_weim_devtype *devtype)
{
u32 cs_idx, value[MAX_CS_REGS_COUNT];
- int i, ret;
+ int i, ret, 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