From mboxrd@z Thu Jan 1 00:00:00 1970 From: kernel@martin.sperl.org (kernel at martin.sperl.org) Date: Tue, 26 Apr 2016 08:56:29 +0000 Subject: [PATCH V2] clk: bcm2835: mark enabled pll_dividers as critical Message-ID: <1461660989-11846-1-git-send-email-kernel@martin.sperl.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Martin Sperl The bcm2835 firmware enables several clocks and plls before booting the linux kernel. These plls should never get disabled as it may result in a stopped system clock and more. So during probing we check if the pll_divider is enabled and if it is then mark that pll_divider as critical. As a consequence this will also enable the corresponding parent pll. Here the list of pll_div that are marked as critical: [ 2.022437] bcm2835-clk 20101000.cprman: found enabled pll_div plla_core - marking it as critical [ 2.031640] bcm2835-clk 20101000.cprman: found enabled pll_div pllb_arm - marking it as critical [ 2.040966] bcm2835-clk 20101000.cprman: found enabled pll_div pllc_core0 - marking it as critical [ 2.050351] bcm2835-clk 20101000.cprman: found enabled pll_div pllc_per - marking it as critical [ 2.059427] bcm2835-clk 20101000.cprman: found enabled pll_div plld_core - marking it as critical [ 2.068590] bcm2835-clk 20101000.cprman: found enabled pll_div plld_per - marking it as critical [ 2.077724] bcm2835-clk 20101000.cprman: found enabled pll_div pllh_pix - marking it as critical Changelog: V1 -> V2: apply to pll_dividers instead of clocks use CLK_IS_CRITICAL flag instead of prepare/enable manually Signed-off-by: Martin Sperl --- drivers/clk/bcm/clk-bcm2835.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c index 6479283c..7f6838f 100644 --- a/drivers/clk/bcm/clk-bcm2835.c +++ b/drivers/clk/bcm/clk-bcm2835.c @@ -1086,6 +1086,15 @@ bcm2835_register_pll_divider(struct bcm2835_cprman *cprman, divider->cprman = cprman; divider->data = data; + /* if the pll-divider is running, then mark is as critical */ + if ((cprman_read(cprman, data->a2w_reg) & + A2W_PLL_CHANNEL_DISABLE) == 0) { + dev_info(cprman->dev, + "found enabled pll_div %s - marking it as critical\n", + data->name); + init.flags |= CLK_IS_CRITICAL; + } + clk = devm_clk_register(cprman->dev, ÷r->div.hw); if (IS_ERR(clk)) return clk; -- 2.1.4