Re: [PATCH] drivers/memory/Kconfig: Add CONFIG_OF dependency

From: Boris Brezillon
Date: Sun Jul 22 2018 - 02:30:06 EST


+Arnd, Rob and the DT ML.

On Sat, 21 Jul 2018 14:53:47 -0700
Randy Dunlap <rdunlap@xxxxxxxxxxxxx> wrote:

> On 07/21/2018 01:00 PM, Anders Roxell wrote:
> > JZ4780_NEMC doesn't depend on OF, and if OF isn't enabled we get this
> > error:
> > drivers/memory/jz4780-nemc.c: In function âjz4780_nemc_num_banksâ:
> > drivers/memory/jz4780-nemc.c:72:10: error: implicit declaration of
> > function âof_read_numberâ; did you mean âdown_read_nestedâ?
> > [-Werror=implicit-function-declaration]
> > bank = of_read_number(prop, 1);
> > ^~~~~~~~~~~~~~
> > down_read_nested

Looks like of.h defines stubs so that people can compile-test without
CONFIG_OF selected. Maybe we should move of_read_number() and
of_read_ulong() out of the #ifdef CONFIG_OF section.

Alternatively, we could patch jz4780-nemc.c to not use of_read_number
and instead rely on of_read_property_u32_index() +
of_property_count_elems_of_size() + of_n_{addr,size}_cells():

--->8---
diff --git a/drivers/memory/jz4780-nemc.c b/drivers/memory/jz4780-nemc.c
index bcf06adefc96..9ad7abc6983a 100644
--- a/drivers/memory/jz4780-nemc.c
+++ b/drivers/memory/jz4780-nemc.c
@@ -63,14 +63,21 @@ struct jz4780_nemc {
*/
unsigned int jz4780_nemc_num_banks(struct device *dev)
{
- const __be32 *prop;
- unsigned int bank, count = 0;
unsigned long referenced = 0;
- int i = 0;
-
- while ((prop = of_get_address(dev->of_node, i++, NULL, NULL))) {
- bank = of_read_number(prop, 1);
- if (!(referenced & BIT(bank))) {
+ int nelems, elemsize, i = 0;
+ unsigned int count = 0;
+
+ /* #address-cells = 2 and #size-cells = 1, hence */
+ elemsize = of_n_addr_cells(dev->of_node) +
+ of_n_size_cells(dev->of_node);
+ nelems = of_property_count_elems_of_size(dev->of_node, "reg", elemsize);
+ for (i = 0; i < nelems; i++) {
+ u32 bank;
+
+ if (!of_property_read_u32_index(dev->of_node, "reg",
+ i * elemsize, &bank) &&
+ bank >= 1 && bank < JZ4780_NEMC_NUM_BANKS &&
+ !(referenced & BIT(bank))) {
referenced |= BIT(bank);
count++;
}
@@ -269,10 +276,9 @@ static int jz4780_nemc_probe(struct platform_device *pdev)
struct jz4780_nemc *nemc;
struct resource *res;
struct device_node *child;
- const __be32 *prop;
- unsigned int bank;
unsigned long referenced;
int i, ret;
+ u32 bank;

nemc = devm_kzalloc(dev, sizeof(*nemc), GFP_KERNEL);
if (!nemc)
@@ -316,10 +322,27 @@ static int jz4780_nemc_probe(struct platform_device *pdev)
* registered for it.
*/
for_each_child_of_node(nemc->dev->of_node, child) {
+ int nelems, elemsize;
+
referenced = 0;
i = 0;
- while ((prop = of_get_address(child, i++, NULL, NULL))) {
- bank = of_read_number(prop, 1);
+ elemsize = of_n_addr_cells(dev->of_node) +
+ of_n_size_cells(dev->of_node);
+ nelems = of_property_count_elems_of_size(dev->of_node, "reg",
+ elemsize);
+ for (i = 0; i < nelems; i++) {
+ u32 bank;
+
+ ret = of_property_read_u32_index(dev->of_node, "reg",
+ i * elemsize, &bank);
+ if (ret) {
+ dev_err(nemc->dev,
+ "failed to read bank %d of %pOF (err = %d)\n",
+ i, child, ret);
+ referenced = 0;
+ break;
+ }
+
if (bank < 1 || bank >= JZ4780_NEMC_NUM_BANKS) {
dev_err(nemc->dev,
"%pOF requests invalid bank %u\n",