Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S937031Ab3DII2B (ORCPT ); Tue, 9 Apr 2013 04:28:01 -0400 Received: from mailbackup.inode.at ([213.229.60.24]:49628 "EHLO mailbackup.inode.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935241Ab3DII17 (ORCPT ); Tue, 9 Apr 2013 04:27:59 -0400 From: Michal Bachraty To: grant.likely@secretlab.ca, rob.herring@calxeda.com, rob@landley.net, mturquette@linaro.org Cc: sebastian.hesselbarth@gmail.com, devicetree-discuss@lists.ozlabs.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Michal Bachraty Subject: [PATCH] clk: si5351: Add gapless tuning for SI5351 PLL Date: Tue, 9 Apr 2013 10:26:15 +0200 Message-Id: <1365495975-792-1-git-send-email-michal.bachraty@streamunlimited.com> X-Mailer: git-send-email 1.7.9.5 X-Authenticated-Sender: michal.bachraty@streamunlimited.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4585 Lines: 125 For gapless tuning, there is no need for PLL reset and clkout power-down when tuning output. "silabs,gapless-tuning" parameter enables gapless tuning for specific clock output. Signed-off-by: Michal Bachraty --- .../devicetree/bindings/clock/silabs,si5351.txt | 2 ++ drivers/clk/clk-si5351.c | 27 +++++++++++++++++--- 2 files changed, 25 insertions(+), 4 deletions(-) diff --git a/Documentation/devicetree/bindings/clock/silabs,si5351.txt b/Documentation/devicetree/bindings/clock/silabs,si5351.txt index cc37465..e16ab2b 100644 --- a/Documentation/devicetree/bindings/clock/silabs,si5351.txt +++ b/Documentation/devicetree/bindings/clock/silabs,si5351.txt @@ -44,6 +44,8 @@ Optional child node properties: - silabs,multisynth-source: source pll A(0) or B(1) of corresponding multisynth divider. - silabs,pll-master: boolean, multisynth can change pll frequency. +- silabs,gapless-tuning: boolean, enable gapless (glitch-free) tuning. Depends on + "silabs,multisynth-source" parameter. ==Example== diff --git a/drivers/clk/clk-si5351.c b/drivers/clk/clk-si5351.c index e259cec..d3933a9 100644 --- a/drivers/clk/clk-si5351.c +++ b/drivers/clk/clk-si5351.c @@ -54,6 +54,7 @@ struct si5351_hw_data { struct si5351_driver_data *drvdata; struct si5351_parameters params; unsigned char num; + unsigned char gapless_tuning; }; struct si5351_driver_data { @@ -526,8 +527,10 @@ static int si5351_pll_set_rate(struct clk_hw *hw, unsigned long rate, (hwdata->params.p2 == 0) ? SI5351_CLK_INTEGER_MODE : 0); /* reset pll */ - val = (hwdata->num == 0) ? SI5351_PLL_RESET_A : SI5351_PLL_RESET_B; - si5351_set_bits(hwdata->drvdata, SI5351_PLL_RESET, val, val); + if (!hwdata->gapless_tuning) { + val = (hwdata->num == 0) ? SI5351_PLL_RESET_A : SI5351_PLL_RESET_B; + si5351_set_bits(hwdata->drvdata, SI5351_PLL_RESET, val, val); + } dev_dbg(&hwdata->drvdata->client->dev, "%s - %s: p1 = %lu, p2 = %lu, p3 = %lu, parent_rate = %lu, rate = %lu\n", @@ -1064,8 +1067,9 @@ static int si5351_clkout_set_rate(struct clk_hw *hw, unsigned long rate, } while (1); /* powerdown clkout */ - si5351_set_bits(hwdata->drvdata, SI5351_CLK0_CTRL + hwdata->num, - SI5351_CLK_POWERDOWN, SI5351_CLK_POWERDOWN); + if (!hwdata->gapless_tuning) + si5351_set_bits(hwdata->drvdata, SI5351_CLK0_CTRL + hwdata->num, + SI5351_CLK_POWERDOWN, SI5351_CLK_POWERDOWN); /* write output divider */ switch (hwdata->num) { @@ -1117,6 +1121,7 @@ static void si5351_dt_setup( struct property *prop; const __be32 *p; unsigned int num, val; + int pll = -1; if (np == NULL) return; @@ -1167,6 +1172,8 @@ static void si5351_dt_setup( dev_warn(&client->dev, "unable to reparent multisynth %d to %d\n", num, val); + else + pll = val; } if (!of_property_read_u32(np, "silabs,clock-source", &val)) { @@ -1178,6 +1185,15 @@ static void si5351_dt_setup( if (!of_property_read_u32(np, "clock-frequency", &val)) clk_set_rate(drvdata->onecell.clks[num], val); + + if (of_property_read_bool(np, "silabs,gapless-tuning")) { + if (pll >= 0) { + drvdata->clkout[num].gapless_tuning = 1; + drvdata->pll[pll].gapless_tuning = 1; + } else + dev_warn(&client->dev, + "unable to set gapless tuning"); + } } } @@ -1294,6 +1310,7 @@ static int si5351_i2c_probe(struct i2c_client *client, drvdata->pll[0].num = 0; drvdata->pll[0].drvdata = drvdata; drvdata->pll[0].hw.init = &init; + drvdata->pll[0].gapless_tuning = 0; memset(&init, 0, sizeof(init)); init.name = si5351_pll_names[0]; init.ops = &si5351_pll_ops; @@ -1310,6 +1327,7 @@ static int si5351_i2c_probe(struct i2c_client *client, drvdata->pll[1].num = 1; drvdata->pll[1].drvdata = drvdata; drvdata->pll[1].hw.init = &init; + drvdata->pll[1].gapless_tuning = 0; memset(&init, 0, sizeof(init)); if (drvdata->variant == SI5351_VARIANT_B) { init.name = si5351_pll_names[2]; @@ -1380,6 +1398,7 @@ static int si5351_i2c_probe(struct i2c_client *client, drvdata->clkout[n].num = n; drvdata->clkout[n].drvdata = drvdata; drvdata->clkout[n].hw.init = &init; + drvdata->clkout[n].gapless_tuning = 0; memset(&init, 0, sizeof(init)); init.name = si5351_clkout_names[n]; init.ops = &si5351_clkout_ops; -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/