mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Eric Anholt <eric@anholt.net>
To: linux-clk@vger.kernel.org
Cc: linux-rpi-kernel@lists.infradead.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	Stephen Warren <swarren@wwwdotorg.org>,
	Lee Jones <lee@kernel.org>, Stephen Boyd <sboyd@codeaurora.org>,
	Mike Turquette <mturquette@baylibre.com>,
	Eric Anholt <eric@anholt.net>,
	stable@vger.kernel.org
Subject: [PATCH 1/2] clk: bcm2835: Fix setting of PLL divider clock rates
Date: Mon, 15 Feb 2016 19:03:57 -0800	[thread overview]
Message-ID: <1455591838-22725-1-git-send-email-eric@anholt.net> (raw)

Our dividers weren't being set successfully because CM_PASSWORD wasn't
included in the register write.  It looks easier to just compute the
divider to write ourselves than to update clk-divider for the ability
to OR in some arbitrary bits on write.

Fixes about half of the video modes on my HDMI monitor (everything
except 720x400).

Cc: stable@vger.kernel.org
Signed-off-by: Eric Anholt <eric@anholt.net>
---
 drivers/clk/bcm/clk-bcm2835.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c
index 015e687..9f4df8f 100644
--- a/drivers/clk/bcm/clk-bcm2835.c
+++ b/drivers/clk/bcm/clk-bcm2835.c
@@ -1107,13 +1107,15 @@ static int bcm2835_pll_divider_set_rate(struct clk_hw *hw,
 	struct bcm2835_pll_divider *divider = bcm2835_pll_divider_from_hw(hw);
 	struct bcm2835_cprman *cprman = divider->cprman;
 	const struct bcm2835_pll_divider_data *data = divider->data;
-	u32 cm;
-	int ret;
+	u32 cm, div, max_div = 1 << A2W_PLL_DIV_BITS;
 
-	ret = clk_divider_ops.set_rate(hw, rate, parent_rate);
-	if (ret)
-		return ret;
+	div = DIV_ROUND_UP_ULL(parent_rate, rate);
+
+	div = min(div, max_div);
+	if (div == max_div)
+		div = 0;
 
+	cprman_write(cprman, data->a2w_reg, div);
 	cm = cprman_read(cprman, data->cm_reg);
 	cprman_write(cprman, data->cm_reg, cm | data->load_mask);
 	cprman_write(cprman, data->cm_reg, cm & ~data->load_mask);
-- 
2.7.0

             reply	other threads:[~2016-02-16  3:04 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-16  3:03 Eric Anholt [this message]
2016-02-16  3:03 ` [PATCH 2/2] clk: bcm2835: Reuse CLK_DIVIDER_MAX_AT_ZERO for recalc_rate() Eric Anholt
2016-02-16 21:45   ` Michael Turquette
2016-02-16 21:44 ` [PATCH 1/2] clk: bcm2835: Fix setting of PLL divider clock rates Michael Turquette

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1455591838-22725-1-git-send-email-eric@anholt.net \
    --to=eric@anholt.net \
    --cc=lee@kernel.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-clk@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-rpi-kernel@lists.infradead.org \
    --cc=mturquette@baylibre.com \
    --cc=sboyd@codeaurora.org \
    --cc=stable@vger.kernel.org \
    --cc=swarren@wwwdotorg.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

all inboxes | Powered by JetHome®