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path: root/drivers/bus/imx-weim.c
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Diffstat (limited to 'drivers/bus/imx-weim.c')
-rw-r--r--drivers/bus/imx-weim.c70
1 files changed, 57 insertions, 13 deletions
diff --git a/drivers/bus/imx-weim.c b/drivers/bus/imx-weim.c
index d84996a4528e..db74334ca5ef 100644
--- a/drivers/bus/imx-weim.c
+++ b/drivers/bus/imx-weim.c
@@ -46,6 +46,17 @@ static const struct imx_weim_devtype imx51_weim_devtype = {
};
#define MAX_CS_REGS_COUNT 6
+#define MAX_CS_COUNT 6
+#define OF_REG_SIZE 3
+
+struct cs_timing {
+ bool is_applied;
+ u32 regs[MAX_CS_REGS_COUNT];
+};
+
+struct cs_timing_state {
+ struct cs_timing cs[MAX_CS_COUNT];
+};
static const struct of_device_id weim_id_table[] = {
/* i.MX1/21 */
@@ -111,21 +122,19 @@ err:
}
/* 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)
+static int __init weim_timing_setup(struct device *dev,
+ struct device_node *np, void __iomem *base,
+ const struct imx_weim_devtype *devtype,
+ struct cs_timing_state *ts)
{
u32 cs_idx, value[MAX_CS_REGS_COUNT];
int i, ret;
+ int reg_idx, num_regs;
+ struct cs_timing *cst;
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);
- if (ret)
- return ret;
-
- if (cs_idx >= devtype->cs_count)
+ if (WARN_ON(devtype->cs_count > MAX_CS_COUNT))
return -EINVAL;
ret = of_property_read_u32_array(np, "fsl,weim-cs-timing",
@@ -133,9 +142,43 @@ static int __init weim_timing_setup(struct device_node *np, void __iomem *base,
if (ret)
return ret;
- /* 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);
+ /*
+ * 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;
+
+ if (cs_idx >= devtype->cs_count)
+ return -EINVAL;
+
+ /* prevent re-configuring a CS that's already been configured */
+ cst = &ts->cs[cs_idx];
+ if (cst->is_applied && memcmp(value, cst->regs,
+ devtype->cs_regs_count * sizeof(u32))) {
+ dev_err(dev, "fsl,weim-cs-timing conflict on %pOF", np);
+ 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);
+ if (!cst->is_applied) {
+ cst->is_applied = true;
+ memcpy(cst->regs, value,
+ devtype->cs_regs_count * sizeof(u32));
+ }
+ }
return 0;
}
@@ -148,6 +191,7 @@ static int __init weim_parse_dt(struct platform_device *pdev,
const struct imx_weim_devtype *devtype = of_id->data;
struct device_node *child;
int ret, have_child = 0;
+ struct cs_timing_state ts = {};
if (devtype == &imx50_weim_devtype) {
ret = imx_weim_gpr_setup(pdev);
@@ -156,7 +200,7 @@ static int __init weim_parse_dt(struct platform_device *pdev,
}
for_each_available_child_of_node(pdev->dev.of_node, child) {
- ret = weim_timing_setup(child, base, devtype);
+ ret = weim_timing_setup(&pdev->dev, child, base, devtype, &ts);
if (ret)
dev_warn(&pdev->dev, "%pOF set timing failed.\n",
child);