omap: gpmc-nand: add ability to keep timings defined by the bootloader

Signed-off-by Mike Rapoport <[email protected]>

---
 arch/arm/mach-omap2/gpmc-nand.c        |   19 ++++++++++++++++++- arch/arm/plat-omap/include/plat/nand.h |    1 +

 2 files changed, 19 insertions(+), 1 deletions(-)

arch/arm/mach-omap2/gpmc-nand.c +13 -1

index e57fb29..7c6c027 100644
@@ -22,6 +22,7 @@
  #define WR_RD_PIN_MONITORING   0x00600000
 
  static struct omap_nand_platform_data *gpmc_nand_data;
+static struct gpmc_timings gpmc_default_timings;
 
  static struct resource gpmc_nand_resource = {
        .flags          = IORESOURCE_MEM,

@@ -34,13 +35,24 @@ static struct platform_device gpmc_nand_device = {
        .resource       = &gpmc_nand_resource,
  };
 
+static void gpmc_nand_detect_timings(void)
+{
+       struct gpmc_timings t;
+
+       memset(&t, 0, sizeof(t));
+       gpmc_cs_get_timings(gpmc_nand_data->cs, &gpmc_default_timings);
+}
+
  static int omap2_nand_gpmc_retime(void)
  {
+       struct device *dev = &gpmc_nand_device.dev;
        struct gpmc_timings t;
        int err;
 
-       if (!gpmc_nand_data->gpmc_t)
+       if (!gpmc_nand_data->gpmc_t) {
+               dev_warn(dev, "No timings provided, skipping retime\n");
                return 0;
+       }
 
        memset(&t, 0, sizeof(t));
        t.sync_clk = gpmc_round_ns_to_ticks(gpmc_nand_data->gpmc_t->sync_clk);

Quoted 48 lines · Mike Rapoport

Signed-off-by Mike Rapoport <[email protected]>

---
 arch/arm/mach-omap2/gpmc-nand.c        |   19 ++++++++++++++++++-
 arch/arm/plat-omap/include/plat/nand.h |    1 +
 2 files changed, 19 insertions(+), 1 deletions(-)

arch/arm/mach-omap2/gpmc-nand.c +13 -1

index e57fb29..7c6c027 100644
@@ -22,6 +22,7 @@
 #define WR_RD_PIN_MONITORING   0x00600000
 
 static struct omap_nand_platform_data *gpmc_nand_data;
+static struct gpmc_timings gpmc_default_timings;
 
 static struct resource gpmc_nand_resource = {
       .flags          = IORESOURCE_MEM,

@@ -34,13 +35,24 @@ static struct platform_device gpmc_nand_device = {
       .resource       = &gpmc_nand_resource,
 };
 
+static void gpmc_nand_detect_timings(void)
+{
+       struct gpmc_timings t;
+
+       memset(&t, 0, sizeof(t));
+       gpmc_cs_get_timings(gpmc_nand_data->cs, &gpmc_default_timings);
+}
+
 static int omap2_nand_gpmc_retime(void)
 {
+       struct device *dev = &gpmc_nand_device.dev;
       struct gpmc_timings t;
       int err;
 
-       if (!gpmc_nand_data->gpmc_t)
+       if (!gpmc_nand_data->gpmc_t) {
+               dev_warn(dev, "No timings provided, skipping retime\n");
               return 0;
+       }
 
       memset(&t, 0, sizeof(t));
       t.sync_clk = gpmc_round_ns_to_ticks(gpmc_nand_data->gpmc_t->sync_clk);

@@ -112,6 +124,11 @@ int __init gpmc_nand_init(struct omap_nand_platform_data *_nand_data)
               return err;
       }
 

arch/arm/mach-omap2/gpmc-nand.c int __init gpmc_nand_init(struct omap_nand_platform_data *_nand_data) · line 131

Quoted 5 lines

arch/arm/mach-omap2/gpmc-nand.c +5 -0

+       if (gpmc_nand_data->keep_timings) {
+               gpmc_nand_detect_timings();
+               gpmc_nand_data->gpmc_t = &gpmc_default_timings;
+       }
+

I guess moving this part to omap2_nand_gpmc_retime will be a good idea. As there, once we get old/default timings we can simply skip the rounding part and directly jump to setting the timings.

Rest looks fine to me.

Quoted 11 lines · Vimal Singh

Quoted 7 lines · Mike Rapoport

Signed-off-by Mike Rapoport <[email protected]>

+       if (gpmc_nand_data->keep_timings) {
+               gpmc_nand_detect_timings();
+               gpmc_nand_data->gpmc_t = &gpmc_default_timings;
+       }
+

Quoted 3 lines

I guess moving this part to omap2_nand_gpmc_retime will be a good idea. As there, once we get old/default timings we can simply skip the rounding part and directly jump to setting the timings.

This way it would be the same as to pass 'gpmc_nand_data->gpmc_t = NULL'. If I correctly understood the previous comments ([1]), the problem with skipping retime is that when L3 clock changes, the gpmc timings became wrong. So, if we convert old/default timings to nanoseconds early during startup every time retime is called it will use the timing settings in nanoseconds thus yielding proper gpmc registers configuration.

And, if I'm not terribly mistaken retime should be called each time L3 frequency changes, though with current kernel it's not yet the case...

Quoted 12 lines · Mike Rapoport

Quoted 11 lines · Vimal Singh

arch/arm/mach-omap2/gpmc-nand.c int __init gpmc_nand_init(struct omap_nand_platform_data *_nand_data) · line 131

Quoted 6 lines · Mike Rapoport

Signed-off-by Mike Rapoport <[email protected]>

arch/arm/mach-omap2/gpmc-nand.c +5 -0

+       if (gpmc_nand_data->keep_timings) {
+               gpmc_nand_detect_timings();
+               gpmc_nand_data->gpmc_t = &gpmc_default_timings;
+       }
+

I guess moving this part to omap2_nand_gpmc_retime will be a good idea. As there, once we get old/default timings we can simply skip the rounding part and directly jump to setting the timings.

Quoted 7 lines

This way it would be the same as to pass 'gpmc_nand_data->gpmc_t = NULL'. If I correctly understood the previous comments ([1]), the problem with skipping retime is that when L3 clock changes, the gpmc timings became wrong. So, if we convert old/default timings to nanoseconds early during startup every time retime is called it will use the timing settings in nanoseconds thus yielding proper gpmc registers configuration.

OK. Then I think we can at least put __rounding__ code inside an 'if' case, something like:
if (!gpmc_nand_data->keep_timings) {
...
do rounding for supplied timings from board file.
...
}

Quoted 2 lines

And, if I'm not terribly mistaken retime should be called each time L3 frequency changes, though with current kernel it's not yet the case...

Yes. This is still left.