Improvements for the Raspberry Pi 3+, Fixes and minor improvements to Raspberry Pi 2/3

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)