Re: [PATCH 07/26] clk: vt8500: parse pmc_base from clock driver
From: Sebastian Hesselbarth
Date: Fri Sep 20 2013 - 02:24:03 EST
On 09/20/2013 06:51 AM, Tony Prisk wrote:
On 20/09/13 07:12, Sebastian Hesselbarth wrote:
On 09/19/2013 09:02 PM, Tony Prisk wrote:
On 19/09/13 05:53, Sebastian Hesselbarth wrote:
Currently, clock providers for vt8500 depend on machine_init providing
pmc_base address before calling of_clk_init. With upcoming arch-wide
.time_init calling of_clk_init, we should make clock providers
independent
of mach code. This adds a pmc_base parsing helper to current clock
provider
that gets called if there is no pmc_base set, yet.
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@xxxxxxxxx>
---
Cc: Olof Johansson <olof@xxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Tony Prisk <linux@xxxxxxxxxxxxxxx>
Cc: Mike Turquette <mturquette@xxxxxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
drivers/clk/clk-vt8500.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/drivers/clk/clk-vt8500.c b/drivers/clk/clk-vt8500.c
index 82306f5..a5ee01c 100644
--- a/drivers/clk/clk-vt8500.c
+++ b/drivers/clk/clk-vt8500.c
@@ -15,11 +15,14 @@
#include <linux/io.h>
#include <linux/of.h>
+#include <linux/of_address.h>
#include <linux/slab.h>
#include <linux/bitops.h>
#include <linux/clkdev.h>
#include <linux/clk-provider.h>
+#define LEGACY_PMC_BASE 0xD8130000
+
/* All clocks share the same lock as none can be changed
concurrently */
static DEFINE_SPINLOCK(_lock);
@@ -626,6 +629,21 @@ const struct clk_ops vtwm_pll_ops = {
.recalc_rate = vtwm_pll_recalc_rate,
};
+static __init void vtwm_set_pmc_base(void)
+{
+ struct device_node *np =
+ of_find_compatible_node(NULL, NULL, "via,vt8500-pmc");
+
+ if (np)
+ pmc_base = of_iomap(np, 0);
+ else
+ pmc_base = ioremap(LEGACY_PMC_BASE, 0x1000);
+ of_node_put(np);
+
+ if (!pmc_base)
+ pr_err("%s:of_iomap(pmc) failed\n", __func__);
+}
+
static __init void vtwm_pll_clk_init(struct device_node *node, int
pll_type)
{
u32 reg;
@@ -636,6 +654,9 @@ static __init void vtwm_pll_clk_init(struct
device_node *node, int pll_type)
struct clk_init_data init;
int rc;
+ if (!pmc_base)
+ vtwm_set_pmc_base();
+
rc = of_property_read_u32(node, "reg", ®);
if (WARN_ON(rc))
return;
What happens if the first clock registered is a 'device clock' rather
than a 'pll'?
static __init void vtwm_device_clk_init(struct device_node *node)
{
u32 en_reg, div_reg;
struct clk *clk;
struct clk_device *dev_clk;
const char *clk_name = node->name;
const char *parent_name;
struct clk_init_data init;
int rc;
int clk_init_flags = 0;
dev_clk = kzalloc(sizeof(*dev_clk), GFP_KERNEL);
if (WARN_ON(!dev_clk))
return;
dev_clk->lock = &_lock;
rc = of_property_read_u32(node, "enable-reg", &en_reg);
if (!rc) {
dev_clk->en_reg = pmc_base + en_reg;
...
}
CLK_OF_DECLARE(vt8500_device, "via,vt8500-device-clock",
vtwm_device_clk_init);
If a device clock is initialized first, pmc_base will be null and
dev_clk->en_reg (+ other register offsets) will be incorrect.
Tony,
looks like I just missed to add the same check for !pmc_base to
vtwm_device_clk_init. If you are ok with the general approach,
I send v2 for this patch shortly.
Optionally, you can also choose to take care of clk-vt8500 yourself,
as mach-vt8500 has its own .init_time callback and will be unaffected
by the arch-wide default callback. If so, I will drop vt8500 to not
stall this series too much now.
Sebastian
I have no issue with the concept - just pointing out the missing bit. If
you can fix that small issue for v2 then you can also add my:
Acked-by: Tony Prisk <linux@xxxxxxxxxxxxxxx>
Just to make sure, does that also count for the other vt8500 patches?
Sebastian
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