drivers/clk/bcm/clk-bcm281xx.c breaks on GCC 4.6.4 (and earlier)

Commit Message

Alex Elder April 7, 2014, 1:25 p.m. UTC

On 04/07/2014 04:26 AM, Russell King - ARM Linux wrote:
> So this greeted me this morning...

Russell, can you try the attached patch to verify it resolves
your errors?  If so I'll send it to Linus as an urgent update.

					-Alex

> drivers/clk/bcm/clk-bcm281xx.c:30:2: error: unknown field 'offset' specified in initializer
> drivers/clk/bcm/clk-bcm281xx.c:30:2: error: unknown field 'shift' specified in initializer
> drivers/clk/bcm/clk-bcm281xx.c:30:2: error: unknown field 'width' specified in initializer
> drivers/clk/bcm/clk-bcm281xx.c:30:2: error: unknown field 'frac_width' specified in initializer
> drivers/clk/bcm/clk-bcm281xx.c:30:2: error: unknown field 'scaled_div' specified in initializer

. . .

Patch

From b59e55ee597c49d65968eca6bc1b003c4a1ae48c Mon Sep 17 00:00:00 2001
From: Alex Elder <[e-mail]>
Date: Mon, 7 Apr 2014 08:22:12 -0500
Subject: [PATCH] clk: bcm281xx: don't use unnamed structs or unions

The Broadcom Kona clock code, as originally written, made use of
unnamed union and struct fields.  This is a feature present in C11,
and is a GNU extension otherwise.  It worked very well for me.

Unfortunately, Russell King reported that this feature was not
supported in a build environment he used, which meant attempting
to build this code failed spectacularly.

Add names to these unnamed fields, and update the code accordingly.

Signed-off-by: Alex Elder <[e-mail]>
---
 drivers/clk/bcm/clk-kona-setup.c |   33 ++++++++++----------
 drivers/clk/bcm/clk-kona.c       |   64 ++++++++++++++++++++------------------
 drivers/clk/bcm/clk-kona.h       |   28 ++++++++---------
 3 files changed, 64 insertions(+), 61 deletions(-)

diff --git a/drivers/clk/bcm/clk-kona-setup.c b/drivers/clk/bcm/clk-kona-setup.c
index c7607fe..54a0652 100644
--- a/drivers/clk/bcm/clk-kona-setup.c
+++ b/drivers/clk/bcm/clk-kona-setup.c
@@ -27,7 +27,7 @@  LIST_HEAD(ccu_list);	/* The list of set up CCUs */
 
 static bool clk_requires_trigger(struct kona_clk *bcm_clk)
 {
-	struct peri_clk_data *peri = bcm_clk->peri;
+	struct peri_clk_data *peri = bcm_clk->u.peri;
 	struct bcm_clk_sel *sel;
 	struct bcm_clk_div *div;
 
@@ -63,7 +63,7 @@  static bool peri_clk_data_offsets_valid(struct kona_clk *bcm_clk)
 	u32 limit;
 
 	BUG_ON(bcm_clk->type != bcm_clk_peri);
-	peri = bcm_clk->peri;
+	peri = bcm_clk->u.peri;
 	name = bcm_clk->name;
 	range = bcm_clk->ccu->range;
 
@@ -81,19 +81,19 @@  static bool peri_clk_data_offsets_valid(struct kona_clk *bcm_clk)
 
 	div = &peri->div;
 	if (divider_exists(div)) {
-		if (div->offset > limit) {
+		if (div->u.s.offset > limit) {
 			pr_err("%s: bad divider offset for %s (%u > %u)\n",
-				__func__, name, div->offset, limit);
+				__func__, name, div->u.s.offset, limit);
 			return false;
 		}
 	}
 
 	div = &peri->pre_div;
 	if (divider_exists(div)) {
-		if (div->offset > limit) {
+		if (div->u.s.offset > limit) {
 			pr_err("%s: bad pre-divider offset for %s "
 					"(%u > %u)\n",
-				__func__, name, div->offset, limit);
+				__func__, name, div->u.s.offset, limit);
 			return false;
 		}
 	}
@@ -249,21 +249,22 @@  static bool div_valid(struct bcm_clk_div *div, const char *field_name,
 {
 	if (divider_is_fixed(div)) {
 		/* Any fixed divider value but 0 is OK */
-		if (div->fixed == 0) {
+		if (div->u.fixed == 0) {
 			pr_err("%s: bad %s fixed value 0 for %s\n", __func__,
 				field_name, clock_name);
 			return false;
 		}
 		return true;
 	}
-	if (!bitfield_valid(div->shift, div->width, field_name, clock_name))
+	if (!bitfield_valid(div->u.s.shift, div->u.s.width,
+				field_name, clock_name))
 		return false;
 
 	if (divider_has_fraction(div))
-		if (div->frac_width > div->width) {
+		if (div->u.s.frac_width > div->u.s.width) {
 			pr_warn("%s: bad %s fraction width for %s (%u > %u)\n",
 				__func__, field_name, clock_name,
-				div->frac_width, div->width);
+				div->u.s.frac_width, div->u.s.width);
 			return false;
 		}
 
@@ -278,7 +279,7 @@  static bool div_valid(struct bcm_clk_div *div, const char *field_name,
  */
 static bool kona_dividers_valid(struct kona_clk *bcm_clk)
 {
-	struct peri_clk_data *peri = bcm_clk->peri;
+	struct peri_clk_data *peri = bcm_clk->u.peri;
 	struct bcm_clk_div *div;
 	struct bcm_clk_div *pre_div;
 	u32 limit;
@@ -295,7 +296,7 @@  static bool kona_dividers_valid(struct kona_clk *bcm_clk)
 
 	limit = BITS_PER_BYTE * sizeof(u32);
 
-	return div->frac_width + pre_div->frac_width <= limit;
+	return div->u.s.frac_width + pre_div->u.s.frac_width <= limit;
 }
 
 
@@ -328,7 +329,7 @@  peri_clk_data_valid(struct kona_clk *bcm_clk)
 	if (!peri_clk_data_offsets_valid(bcm_clk))
 		return false;
 
-	peri = bcm_clk->peri;
+	peri = bcm_clk->u.peri;
 	name = bcm_clk->name;
 	gate = &peri->gate;
 	if (gate_exists(gate) && !gate_valid(gate, "gate", name))
@@ -588,12 +589,12 @@  static void bcm_clk_teardown(struct kona_clk *bcm_clk)
 {
 	switch (bcm_clk->type) {
 	case bcm_clk_peri:
-		peri_clk_teardown(bcm_clk->data, &bcm_clk->init_data);
+		peri_clk_teardown(bcm_clk->u.data, &bcm_clk->init_data);
 		break;
 	default:
 		break;
 	}
-	bcm_clk->data = NULL;
+	bcm_clk->u.data = NULL;
 	bcm_clk->type = bcm_clk_none;
 }
 
@@ -644,7 +645,7 @@  struct clk *kona_clk_setup(struct ccu_data *ccu, const char *name,
 		break;
 	}
 	bcm_clk->type = type;
-	bcm_clk->data = data;
+	bcm_clk->u.data = data;
 
 	/* Make sure everything makes sense before we set it up */
 	if (!kona_clk_valid(bcm_clk)) {
diff --git a/drivers/clk/bcm/clk-kona.c b/drivers/clk/bcm/clk-kona.c
index e3d339e..db11a87 100644
--- a/drivers/clk/bcm/clk-kona.c
+++ b/drivers/clk/bcm/clk-kona.c
@@ -61,7 +61,7 @@  u64 do_div_round_closest(u64 dividend, unsigned long divisor)
 /* Convert a divider into the scaled divisor value it represents. */
 static inline u64 scaled_div_value(struct bcm_clk_div *div, u32 reg_div)
 {
-	return (u64)reg_div + ((u64)1 << div->frac_width);
+	return (u64)reg_div + ((u64)1 << div->u.s.frac_width);
 }
 
 /*
@@ -77,7 +77,7 @@  u64 scaled_div_build(struct bcm_clk_div *div, u32 div_value, u32 billionths)
 	BUG_ON(billionths >= BILLION);
 
 	combined = (u64)div_value * BILLION + billionths;
-	combined <<= div->frac_width;
+	combined <<= div->u.s.frac_width;
 
 	return do_div_round_closest(combined, BILLION);
 }
@@ -87,7 +87,7 @@  static inline u64
 scaled_div_min(struct bcm_clk_div *div)
 {
 	if (divider_is_fixed(div))
-		return (u64)div->fixed;
+		return (u64)div->u.fixed;
 
 	return scaled_div_value(div, 0);
 }
@@ -98,9 +98,9 @@  u64 scaled_div_max(struct bcm_clk_div *div)
 	u32 reg_div;
 
 	if (divider_is_fixed(div))
-		return (u64)div->fixed;
+		return (u64)div->u.fixed;
 
-	reg_div = ((u32)1 << div->width) - 1;
+	reg_div = ((u32)1 << div->u.s.width) - 1;
 
 	return scaled_div_value(div, reg_div);
 }
@@ -115,7 +115,7 @@  divider(struct bcm_clk_div *div, u64 scaled_div)
 	BUG_ON(scaled_div < scaled_div_min(div));
 	BUG_ON(scaled_div > scaled_div_max(div));
 
-	return (u32)(scaled_div - ((u64)1 << div->frac_width));
+	return (u32)(scaled_div - ((u64)1 << div->u.s.frac_width));
 }
 
 /* Return a rate scaled for use when dividing by a scaled divisor. */
@@ -125,7 +125,7 @@  scale_rate(struct bcm_clk_div *div, u32 rate)
 	if (divider_is_fixed(div))
 		return (u64)rate;
 
-	return (u64)rate << div->frac_width;
+	return (u64)rate << div->u.s.frac_width;
 }
 
 /* CCU access */
@@ -398,14 +398,14 @@  static u64 divider_read_scaled(struct ccu_data *ccu, struct bcm_clk_div *div)
 	u32 reg_div;
 
 	if (divider_is_fixed(div))
-		return (u64)div->fixed;
+		return (u64)div->u.fixed;
 
 	flags = ccu_lock(ccu);
-	reg_val = __ccu_read(ccu, div->offset);
+	reg_val = __ccu_read(ccu, div->u.s.offset);
 	ccu_unlock(ccu, flags);
 
 	/* Extract the full divider field from the register value */
-	reg_div = bitfield_extract(reg_val, div->shift, div->width);
+	reg_div = bitfield_extract(reg_val, div->u.s.shift, div->u.s.width);
 
 	/* Return the scaled divisor value it represents */
 	return scaled_div_value(div, reg_div);
@@ -433,16 +433,17 @@  static int __div_commit(struct ccu_data *ccu, struct bcm_clk_gate *gate,
 	 * state was defined in the device tree, we just find out
 	 * what its current value is rather than updating it.
 	 */
-	if (div->scaled_div == BAD_SCALED_DIV_VALUE) {
-		reg_val = __ccu_read(ccu, div->offset);
-		reg_div = bitfield_extract(reg_val, div->shift, div->width);
-		div->scaled_div = scaled_div_value(div, reg_div);
+	if (div->u.s.scaled_div == BAD_SCALED_DIV_VALUE) {
+		reg_val = __ccu_read(ccu, div->u.s.offset);
+		reg_div = bitfield_extract(reg_val, div->u.s.shift,
+						div->u.s.width);
+		div->u.s.scaled_div = scaled_div_value(div, reg_div);
 
 		return 0;
 	}
 
 	/* Convert the scaled divisor to the value we need to record */
-	reg_div = divider(div, div->scaled_div);
+	reg_div = divider(div, div->u.s.scaled_div);
 
 	/* Clock needs to be enabled before changing the rate */
 	enabled = __is_clk_gate_enabled(ccu, gate);
@@ -452,9 +453,10 @@  static int __div_commit(struct ccu_data *ccu, struct bcm_clk_gate *gate,
 	}
 
 	/* Replace the divider value and record the result */
-	reg_val = __ccu_read(ccu, div->offset);
-	reg_val = bitfield_replace(reg_val, div->shift, div->width, reg_div);
-	__ccu_write(ccu, div->offset, reg_val);
+	reg_val = __ccu_read(ccu, div->u.s.offset);
+	reg_val = bitfield_replace(reg_val, div->u.s.shift, div->u.s.width,
+					reg_div);
+	__ccu_write(ccu, div->u.s.offset, reg_val);
 
 	/* If the trigger fails we still want to disable the gate */
 	if (!__clk_trigger(ccu, trig))
@@ -490,11 +492,11 @@  static int divider_write(struct ccu_data *ccu, struct bcm_clk_gate *gate,
 
 	BUG_ON(divider_is_fixed(div));
 
-	previous = div->scaled_div;
+	previous = div->u.s.scaled_div;
 	if (previous == scaled_div)
 		return 0;	/* No change */
 
-	div->scaled_div = scaled_div;
+	div->u.s.scaled_div = scaled_div;
 
 	flags = ccu_lock(ccu);
 	__ccu_write_enable(ccu);
@@ -505,7 +507,7 @@  static int divider_write(struct ccu_data *ccu, struct bcm_clk_gate *gate,
 	ccu_unlock(ccu, flags);
 
 	if (ret)
-		div->scaled_div = previous;		/* Revert the change */
+		div->u.s.scaled_div = previous;		/* Revert the change */
 
 	return ret;
 
@@ -802,7 +804,7 @@  static int selector_write(struct ccu_data *ccu, struct bcm_clk_gate *gate,
 static int kona_peri_clk_enable(struct clk_hw *hw)
 {
 	struct kona_clk *bcm_clk = to_kona_clk(hw);
-	struct bcm_clk_gate *gate = &bcm_clk->peri->gate;
+	struct bcm_clk_gate *gate = &bcm_clk->u.peri->gate;
 
 	return clk_gate(bcm_clk->ccu, bcm_clk->name, gate, true);
 }
@@ -810,7 +812,7 @@  static int kona_peri_clk_enable(struct clk_hw *hw)
 static void kona_peri_clk_disable(struct clk_hw *hw)
 {
 	struct kona_clk *bcm_clk = to_kona_clk(hw);
-	struct bcm_clk_gate *gate = &bcm_clk->peri->gate;
+	struct bcm_clk_gate *gate = &bcm_clk->u.peri->gate;
 
 	(void)clk_gate(bcm_clk->ccu, bcm_clk->name, gate, false);
 }
@@ -818,7 +820,7 @@  static void kona_peri_clk_disable(struct clk_hw *hw)
 static int kona_peri_clk_is_enabled(struct clk_hw *hw)
 {
 	struct kona_clk *bcm_clk = to_kona_clk(hw);
-	struct bcm_clk_gate *gate = &bcm_clk->peri->gate;
+	struct bcm_clk_gate *gate = &bcm_clk->u.peri->gate;
 
 	return is_clk_gate_enabled(bcm_clk->ccu, gate) ? 1 : 0;
 }
@@ -827,7 +829,7 @@  static unsigned long kona_peri_clk_recalc_rate(struct clk_hw *hw,
 			unsigned long parent_rate)
 {
 	struct kona_clk *bcm_clk = to_kona_clk(hw);
-	struct peri_clk_data *data = bcm_clk->peri;
+	struct peri_clk_data *data = bcm_clk->u.peri;
 
 	return clk_recalc_rate(bcm_clk->ccu, &data->div, &data->pre_div,
 				parent_rate);
@@ -837,20 +839,20 @@  static long kona_peri_clk_round_rate(struct clk_hw *hw, unsigned long rate,
 			unsigned long *parent_rate)
 {
 	struct kona_clk *bcm_clk = to_kona_clk(hw);
-	struct bcm_clk_div *div = &bcm_clk->peri->div;
+	struct bcm_clk_div *div = &bcm_clk->u.peri->div;
 
 	if (!divider_exists(div))
 		return __clk_get_rate(hw->clk);
 
 	/* Quietly avoid a zero rate */
-	return round_rate(bcm_clk->ccu, div, &bcm_clk->peri->pre_div,
+	return round_rate(bcm_clk->ccu, div, &bcm_clk->u.peri->pre_div,
 				rate ? rate : 1, *parent_rate, NULL);
 }
 
 static int kona_peri_clk_set_parent(struct clk_hw *hw, u8 index)
 {
 	struct kona_clk *bcm_clk = to_kona_clk(hw);
-	struct peri_clk_data *data = bcm_clk->peri;
+	struct peri_clk_data *data = bcm_clk->u.peri;
 	struct bcm_clk_sel *sel = &data->sel;
 	struct bcm_clk_trig *trig;
 	int ret;
@@ -884,7 +886,7 @@  static int kona_peri_clk_set_parent(struct clk_hw *hw, u8 index)
 static u8 kona_peri_clk_get_parent(struct clk_hw *hw)
 {
 	struct kona_clk *bcm_clk = to_kona_clk(hw);
-	struct peri_clk_data *data = bcm_clk->peri;
+	struct peri_clk_data *data = bcm_clk->u.peri;
 	u8 index;
 
 	index = selector_read_index(bcm_clk->ccu, &data->sel);
@@ -897,7 +899,7 @@  static int kona_peri_clk_set_rate(struct clk_hw *hw, unsigned long rate,
 			unsigned long parent_rate)
 {
 	struct kona_clk *bcm_clk = to_kona_clk(hw);
-	struct peri_clk_data *data = bcm_clk->peri;
+	struct peri_clk_data *data = bcm_clk->u.peri;
 	struct bcm_clk_div *div = &data->div;
 	u64 scaled_div = 0;
 	int ret;
@@ -958,7 +960,7 @@  struct clk_ops kona_peri_clk_ops = {
 static bool __peri_clk_init(struct kona_clk *bcm_clk)
 {
 	struct ccu_data *ccu = bcm_clk->ccu;
-	struct peri_clk_data *peri = bcm_clk->peri;
+	struct peri_clk_data *peri = bcm_clk->u.peri;
 	const char *name = bcm_clk->name;
 	struct bcm_clk_trig *trig;
 
diff --git a/drivers/clk/bcm/clk-kona.h b/drivers/clk/bcm/clk-kona.h
index 5e139ad..dee6909 100644
--- a/drivers/clk/bcm/clk-kona.h
+++ b/drivers/clk/bcm/clk-kona.h
@@ -57,7 +57,7 @@ 
 #define divider_exists(div)		FLAG_TEST(div, DIV, EXISTS)
 #define divider_is_fixed(div)		FLAG_TEST(div, DIV, FIXED)
 #define divider_has_fraction(div)	(!divider_is_fixed(div) && \
-						(div)->frac_width > 0)
+						(div)->u.s.frac_width > 0)
 
 #define selector_exists(sel)		((sel)->width != 0)
 #define trigger_exists(trig)		FLAG_TEST(trig, TRIG, EXISTS)
@@ -244,9 +244,9 @@  struct bcm_clk_div {
 			u32 frac_width;	/* field fraction width */
 
 			u64 scaled_div;	/* scaled divider value */
-		};
+		} s;
 		u32 fixed;	/* non-zero fixed divider value */
-	};
+	} u;
 	u32 flags;		/* BCM_CLK_DIV_FLAGS_* below */
 };
 
@@ -263,28 +263,28 @@  struct bcm_clk_div {
 /* A fixed (non-zero) divider */
 #define FIXED_DIVIDER(_value)						\
 	{								\
-		.fixed = (_value),					\
+		.u.fixed = (_value),					\
 		.flags = FLAG(DIV, EXISTS)|FLAG(DIV, FIXED),		\
 	}
 
 /* A divider with an integral divisor */
 #define DIVIDER(_offset, _shift, _width)				\
 	{								\
-		.offset = (_offset),					\
-		.shift = (_shift),					\
-		.width = (_width),					\
-		.scaled_div = BAD_SCALED_DIV_VALUE,			\
+		.u.s.offset = (_offset),				\
+		.u.s.shift = (_shift),					\
+		.u.s.width = (_width),					\
+		.u.s.scaled_div = BAD_SCALED_DIV_VALUE,			\
 		.flags = FLAG(DIV, EXISTS),				\
 	}
 
 /* A divider whose divisor has an integer and fractional part */
 #define FRAC_DIVIDER(_offset, _shift, _width, _frac_width)		\
 	{								\
-		.offset = (_offset),					\
-		.shift = (_shift),					\
-		.width = (_width),					\
-		.frac_width = (_frac_width),				\
-		.scaled_div = BAD_SCALED_DIV_VALUE,			\
+		.u.s.offset = (_offset),				\
+		.u.s.shift = (_shift),					\
+		.u.s.width = (_width),					\
+		.u.s.frac_width = (_frac_width),			\
+		.u.s.scaled_div = BAD_SCALED_DIV_VALUE,			\
 		.flags = FLAG(DIV, EXISTS),				\
 	}
 
@@ -380,7 +380,7 @@  struct kona_clk {
 	union {
 		void *data;
 		struct peri_clk_data *peri;
-	};
+	} u;
 };
 #define to_kona_clk(_hw) \
 	container_of(_hw, struct kona_clk, hw)
-- 
1.7.9.5