diff options
Diffstat (limited to 'bcm283x-clk-audio-fixes.patch')
| -rw-r--r-- | bcm283x-clk-audio-fixes.patch | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/bcm283x-clk-audio-fixes.patch b/bcm283x-clk-audio-fixes.patch new file mode 100644 index 000000000..51c9fa791 --- /dev/null +++ b/bcm283x-clk-audio-fixes.patch @@ -0,0 +1,98 @@ +From aa964d59aab2cb04bc011ffd370822ac79f82a0b Mon Sep 17 00:00:00 2001 +From: Boris Brezillon <boris.brezillon@bootlin.com> +Date: Wed, 7 Mar 2018 15:39:17 +0100 +Subject: [PATCH] clk: bcm2835: De-assert/assert PLL reset signal when + appropriate + +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> +--- + drivers/clk/bcm/clk-bcm2835.c | 7 +++++++ + 1 file changed, 7 insertions(+) + +diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c +index a07f6451694a..6c5d4a8e426c 100644 +--- a/drivers/clk/bcm/clk-bcm2835.c ++++ b/drivers/clk/bcm/clk-bcm2835.c +@@ -602,6 +602,9 @@ 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->a2w_ctrl_reg, ++ cprman_read(cprman, data->a2w_ctrl_reg) & ++ ~A2W_PLL_CTRL_PRST_DISABLE); + cprman_write(cprman, data->cm_ctrl_reg, + cprman_read(cprman, data->cm_ctrl_reg) | + CM_PLL_ANARST); +@@ -640,6 +643,10 @@ 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; + } + +From 1b6867ee05d84cc6ec23b5ec0b78684187d3190a Mon Sep 17 00:00:00 2001 +From: Boris Brezillon <boris.brezillon@bootlin.com> +Date: Wed, 7 Mar 2018 15:41:14 +0100 +Subject: [PATCH] clk: bcm2835: Make sure the PLL is gated before changing its + rate + +All bcm2835 PLLs should be gated before their rate can be changed. +Setting CLK_SET_RATE_GATE will let the core enforce that, but this is +not enough to make the code work in all situations. Indeed, the +CLK_SET_RATE_GATE flag prevents a user from changing the rate while +the clock is enabled, but this check only guarantees there's no Linux +users. In our case, the clock might have been enabled by the +bootloader/FW, and, because we have CLK_IGNORE_UNUSED set, Linux never +disables the PLL. So we have to make sure the PLL is actually disabled +before changing the rate. + +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> +--- + drivers/clk/bcm/clk-bcm2835.c | 14 +++++++++++++- + 1 file changed, 13 insertions(+), 1 deletion(-) + +diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c +index 6c5d4a8e426c..051ce769c109 100644 +--- a/drivers/clk/bcm/clk-bcm2835.c ++++ b/drivers/clk/bcm/clk-bcm2835.c +@@ -678,6 +678,18 @@ static int bcm2835_pll_set_rate(struct clk_hw *hw, + u32 ana[4]; + int i; + ++ /* ++ * Normally, the CLK_SET_RATE_GATE flag prevents a user from changing ++ * the rate while the clock is enabled, but this check only makes sure ++ * there's no Linux users. ++ * In our case, the clock might have been enabled by the bootloader/FW, ++ * and, since CLK_IGNORE_UNUSED flag is set, Linux never disables it. ++ * So we have to make sure the clk is actually disabled before changing ++ * the rate. ++ */ ++ if (bcm2835_pll_is_on(hw)) ++ bcm2835_pll_off(hw); ++ + if (rate > data->max_fb_rate) { + use_fb_prediv = true; + rate /= 2; +@@ -1318,7 +1330,7 @@ static struct clk_hw *bcm2835_register_pll(struct bcm2835_cprman *cprman, + init.num_parents = 1; + init.name = data->name; + init.ops = &bcm2835_pll_clk_ops; +- init.flags = CLK_IGNORE_UNUSED; ++ init.flags = CLK_IGNORE_UNUSED | CLK_SET_RATE_GATE; + + pll = kzalloc(sizeof(*pll), GFP_KERNEL); + if (!pll) |