clk: mmp: add spin lock for clk-frac

The register used by clk-frac may be shared with
other clocks.
So it needs to use spin lock to protect the register
access.

Signed-off-by: Chao Xie <chao.xie@marvell.com>
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Signed-off-by: Michael Turquette <mturquette@linaro.org>

drivers/clk/mmp/clk-frac.c

@@ -29,6 +29,7 @@ struct mmp_clk_factor {
 	struct mmp_clk_factor_masks	*masks;
 	struct mmp_clk_factor_tbl	*ftbl;
 	unsigned int		ftbl_cnt;
+	spinlock_t *lock;
 };
 
 static long clk_factor_round_rate(struct clk_hw *hw, unsigned long drate,
@@ -86,6 +87,7 @@ static int clk_factor_set_rate(struct clk_hw *hw, unsigned long drate,
 	int i;
 	unsigned long val;
 	unsigned long prev_rate, rate = 0;
+	unsigned long flags = 0;
 
 	for (i = 0; i < factor->ftbl_cnt; i++) {
 		prev_rate = rate;
@@ -97,6 +99,9 @@ static int clk_factor_set_rate(struct clk_hw *hw, unsigned long drate,
 	if (i > 0)
 		i--;
 
+	if (factor->lock)
+		spin_lock_irqsave(factor->lock, flags);
+
 	val = readl_relaxed(factor->base);
 
 	val &= ~(masks->num_mask << masks->num_shift);
@@ -107,6 +112,9 @@ static int clk_factor_set_rate(struct clk_hw *hw, unsigned long drate,
 
 	writel_relaxed(val, factor->base);
 
+	if (factor->lock)
+		spin_unlock_irqrestore(factor->lock, flags);
+
 	return 0;
 }
 
@@ -120,7 +128,7 @@ struct clk *mmp_clk_register_factor(const char *name, const char *parent_name,
 		unsigned long flags, void __iomem *base,
 		struct mmp_clk_factor_masks *masks,
 		struct mmp_clk_factor_tbl *ftbl,
-		unsigned int ftbl_cnt)
+		unsigned int ftbl_cnt, spinlock_t *lock)
 {
 	struct mmp_clk_factor *factor;
 	struct clk_init_data init;
@@ -143,6 +151,7 @@ struct clk *mmp_clk_register_factor(const char *name, const char *parent_name,
 	factor->ftbl = ftbl;
 	factor->ftbl_cnt = ftbl_cnt;
 	factor->hw.init = &init;
+	factor->lock = lock;
 
 	init.name = name;
 	init.ops = &clk_factor_ops;

drivers/clk/mmp/clk-mmp2.c

@@ -191,7 +191,7 @@ void __init mmp2_clk_init(void)
 	clk = mmp_clk_register_factor("uart_pll", "pll1_4", 0,
 				mpmu_base + MPMU_UART_PLL,
 				&uart_factor_masks, uart_factor_tbl,
-				ARRAY_SIZE(uart_factor_tbl));
+				ARRAY_SIZE(uart_factor_tbl), &clk_lock);
 	clk_set_rate(clk, 14745600);
 	clk_register_clkdev(clk, "uart_pll", NULL);
 

drivers/clk/mmp/clk-pxa168.c

@@ -158,7 +158,7 @@ void __init pxa168_clk_init(void)
 	uart_pll = mmp_clk_register_factor("uart_pll", "pll1_4", 0,
 				mpmu_base + MPMU_UART_PLL,
 				&uart_factor_masks, uart_factor_tbl,
-				ARRAY_SIZE(uart_factor_tbl));
+				ARRAY_SIZE(uart_factor_tbl), &clk_lock);
 	clk_set_rate(uart_pll, 14745600);
 	clk_register_clkdev(uart_pll, "uart_pll", NULL);
 

drivers/clk/mmp/clk-pxa910.c

@@ -163,7 +163,7 @@ void __init pxa910_clk_init(void)
 	uart_pll =  mmp_clk_register_factor("uart_pll", "pll1_4", 0,
 				mpmu_base + MPMU_UART_PLL,
 				&uart_factor_masks, uart_factor_tbl,
-				ARRAY_SIZE(uart_factor_tbl));
+				ARRAY_SIZE(uart_factor_tbl), &clk_lock);
 	clk_set_rate(uart_pll, 14745600);
 	clk_register_clkdev(uart_pll, "uart_pll", NULL);
 

drivers/clk/mmp/clk.h

@@ -31,5 +31,6 @@ extern struct clk *mmp_clk_register_apmu(const char *name,
 extern struct clk *mmp_clk_register_factor(const char *name,
 		const char *parent_name, unsigned long flags,
 		void __iomem *base, struct mmp_clk_factor_masks *masks,
-		struct mmp_clk_factor_tbl *ftbl, unsigned int ftbl_cnt);
+		struct mmp_clk_factor_tbl *ftbl, unsigned int ftbl_cnt,
+		spinlock_t *lock);
 #endif