clk: bcm2835: Protect sections updating shared registers

CM_PLLx and A2W_XOSC_CTRL registers are accessed by different clock
handlers and must be accessed with ->regs_lock held.
Update the sections where this protection is missing.

Fixes: 41691b88 ("clk: bcm2835: Add support for programming the audio domain clocks")
Cc: <stable@vger.kernel.org>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/bcm/clk-bcm2835.c

@@ -623,8 +623,10 @@ static int bcm2835_pll_on(struct clk_hw *hw)
 		     ~A2W_PLL_CTRL_PWRDN);
 
 	/* Take the PLL out of reset. */
+	spin_lock(&cprman->regs_lock);
 	cprman_write(cprman, data->cm_ctrl_reg,
 		     cprman_read(cprman, data->cm_ctrl_reg) & ~CM_PLL_ANARST);
+	spin_unlock(&cprman->regs_lock);
 
 	/* Wait for the PLL to lock. */
 	timeout = ktime_add_ns(ktime_get(), LOCK_TIMEOUT_NS);
@@ -701,9 +703,11 @@ static int bcm2835_pll_set_rate(struct clk_hw *hw,
 	}
 
 	/* Unmask the reference clock from the oscillator. */
+	spin_lock(&cprman->regs_lock);
 	cprman_write(cprman, A2W_XOSC_CTRL,
 		     cprman_read(cprman, A2W_XOSC_CTRL) |
 		     data->reference_enable_mask);
+	spin_unlock(&cprman->regs_lock);
 
 	if (do_ana_setup_first)
 		bcm2835_pll_write_ana(cprman, data->ana_reg_base, ana);