clk: bcm2835: De-assert/assert PLL reset signal when appropriate
authorBoris Brezillon <boris.brezillon@bootlin.com>
Thu, 22 Mar 2018 09:11:30 +0000 (10:11 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 24 Apr 2018 07:36:34 +0000 (09:36 +0200)
commit 753872373b599384ac7df809aa61ea12d1c4d5d1 upstream.

In order to enable a PLL, not only the PLL has to be powered up and
locked, but you also have to de-assert the reset signal. The last part
was missing. Add it so PLLs that were not enabled by the FW/bootloader
can be enabled from Linux.

Fixes: 41691b8862e2 ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/clk/bcm/clk-bcm2835.c

index eec52734d6ac0b372fec3ba4ecd338e123cb5b16..5f8082d89131307744cafa84c2167c0a59c4c979 100644 (file)
@@ -632,9 +632,7 @@ static void bcm2835_pll_off(struct clk_hw *hw)
        const struct bcm2835_pll_data *data = pll->data;
 
        spin_lock(&cprman->regs_lock);
-       cprman_write(cprman, data->cm_ctrl_reg,
-                    cprman_read(cprman, data->cm_ctrl_reg) |
-                    CM_PLL_ANARST);
+       cprman_write(cprman, data->cm_ctrl_reg, CM_PLL_ANARST);
        cprman_write(cprman, data->a2w_ctrl_reg,
                     cprman_read(cprman, data->a2w_ctrl_reg) |
                     A2W_PLL_CTRL_PWRDN);
@@ -670,6 +668,10 @@ static int bcm2835_pll_on(struct clk_hw *hw)
                cpu_relax();
        }
 
+       cprman_write(cprman, data->a2w_ctrl_reg,
+                    cprman_read(cprman, data->a2w_ctrl_reg) |
+                    A2W_PLL_CTRL_PRST_DISABLE);
+
        return 0;
 }