[PATCH 2/2] clk: qoriq: Separate root input clock for core PLLs on ls1012a

From: yuantian.tang
Date: Wed Feb 15 2017 - 01:02:32 EST


From: Tang Yuantian <Yuantian.Tang@xxxxxxx>

ls1012a has separate input root clocks for core PLLs versus the
platform PLL, with the latter described as sysclk in the hw docs.
If a second input clock, named "coreclk", is present, this clock will be
used for the core PLLs.

Signed-off-by: Scott Wood <oss@xxxxxxxxxxxx>
Signed-off-by: Tang Yuantian <yuantian.tang@xxxxxxx>
---
drivers/clk/clk-qoriq.c | 91 +++++++++++++++++++++++++++++++++++++++++--------
1 file changed, 77 insertions(+), 14 deletions(-)

diff --git a/drivers/clk/clk-qoriq.c b/drivers/clk/clk-qoriq.c
index d0bf8b1..f3931e3 100644
--- a/drivers/clk/clk-qoriq.c
+++ b/drivers/clk/clk-qoriq.c
@@ -87,7 +87,7 @@ struct clockgen {
struct device_node *node;
void __iomem *regs;
struct clockgen_chipinfo info; /* mutable copy */
- struct clk *sysclk;
+ struct clk *sysclk, *coreclk;
struct clockgen_pll pll[6];
struct clk *cmux[NUM_CMUX];
struct clk *hwaccel[NUM_HWACCEL];
@@ -904,7 +904,12 @@ static void __init create_muxes(struct clockgen *cg)

static void __init clockgen_init(struct device_node *np);

-/* Legacy nodes may get probed before the parent clockgen node */
+/*
+ * Legacy nodes may get probed before the parent clockgen node.
+ * It is assumed that device trees with legacy nodes will not
+ * contain a "clocks" property -- otherwise the input clocks may
+ * not be initialized at this point.
+ */
static void __init legacy_init_clockgen(struct device_node *np)
{
if (!clockgen.node)
@@ -945,18 +950,13 @@ static struct clk __init
return clk_register_fixed_rate(NULL, name, NULL, 0, rate);
}

-static struct clk *sysclk_from_parent(const char *name)
+static struct clk __init *input_clock(const char *name, struct clk *clk)
{
- struct clk *clk;
- const char *parent_name;
-
- clk = of_clk_get(clockgen.node, 0);
- if (IS_ERR(clk))
- return clk;
+ const char *input_name;

/* Register the input clock under the desired name. */
- parent_name = __clk_get_name(clk);
- clk = clk_register_fixed_factor(NULL, name, parent_name,
+ input_name = __clk_get_name(clk);
+ clk = clk_register_fixed_factor(NULL, name, input_name,
0, 1, 1);
if (IS_ERR(clk))
pr_err("%s: Couldn't register %s: %ld\n", __func__, name,
@@ -965,6 +965,29 @@ static struct clk *sysclk_from_parent(const char *name)
return clk;
}

+static struct clk __init *input_clock_by_name(const char *name,
+ const char *dtname)
+{
+ struct clk *clk;
+
+ clk = of_clk_get_by_name(clockgen.node, dtname);
+ if (IS_ERR(clk))
+ return clk;
+
+ return input_clock(name, clk);
+}
+
+static struct clk __init *input_clock_by_index(const char *name, int idx)
+{
+ struct clk *clk;
+
+ clk = of_clk_get(clockgen.node, 0);
+ if (IS_ERR(clk))
+ return clk;
+
+ return input_clock(name, clk);
+}
+
static struct clk * __init create_sysclk(const char *name)
{
struct device_node *sysclk;
@@ -974,7 +997,11 @@ static struct clk * __init create_sysclk(const char *name)
if (!IS_ERR(clk))
return clk;

- clk = sysclk_from_parent(name);
+ clk = input_clock_by_name(name, "sysclk");
+ if (!IS_ERR(clk))
+ return clk;
+
+ clk = input_clock_by_index(name, 0);
if (!IS_ERR(clk))
return clk;

@@ -985,7 +1012,27 @@ static struct clk * __init create_sysclk(const char *name)
return clk;
}

- pr_err("%s: No input clock\n", __func__);
+ pr_err("%s: No input sysclk\n", __func__);
+ return NULL;
+}
+
+static struct clk * __init create_coreclk(const char *name)
+{
+ struct clk *clk;
+
+ clk = input_clock_by_name(name, "coreclk");
+ if (!IS_ERR(clk))
+ return clk;
+
+ /*
+ * This indicates a mix of legacy nodes with the new coreclk
+ * mechanism, which should never happen. If this error occurs,
+ * don't use the wrong input clock just because coreclk isn't
+ * ready yet.
+ */
+ if (WARN_ON(PTR_ERR(clk) == -EPROBE_DEFER))
+ return clk;
+
return NULL;
}

@@ -1008,11 +1055,19 @@ static void __init create_one_pll(struct clockgen *cg, int idx)
u32 __iomem *reg;
u32 mult;
struct clockgen_pll *pll = &cg->pll[idx];
+ const char *input = "cg-sysclk";
int i;

if (!(cg->info.pll_mask & (1 << idx)))
return;

+ if (cg->coreclk && idx != PLATFORM_PLL) {
+ if (IS_ERR(cg->coreclk))
+ return;
+
+ input = "cg-coreclk";
+ }
+
if (cg->info.flags & CG_VER3) {
switch (idx) {
case PLATFORM_PLL:
@@ -1063,7 +1118,7 @@ static void __init create_one_pll(struct clockgen *cg, int idx)
"cg-pll%d-div%d", idx, i + 1);

clk = clk_register_fixed_factor(NULL,
- pll->div[i].name, "cg-sysclk", 0, mult, i + 1);
+ pll->div[i].name, input, 0, mult, i + 1);
if (IS_ERR(clk)) {
pr_err("%s: %s: register failed %ld\n",
__func__, pll->div[i].name, PTR_ERR(clk));
@@ -1200,6 +1255,13 @@ static struct clk *clockgen_clk_get(struct of_phandle_args *clkspec, void *data)
goto bad_args;
clk = pll->div[idx].clk;
break;
+ case 5:
+ if (idx != 0)
+ goto bad_args;
+ clk = cg->coreclk;
+ if (IS_ERR(clk))
+ clk = NULL;
+ break;
default:
goto bad_args;
}
@@ -1311,6 +1373,7 @@ static void __init clockgen_init(struct device_node *np)
clockgen.info.flags |= CG_CMUX_GE_PLAT;

clockgen.sysclk = create_sysclk("cg-sysclk");
+ clockgen.coreclk = create_coreclk("cg-coreclk");
create_plls(&clockgen);
create_muxes(&clockgen);

--
2.1.0.27.g96db324