Commit 4946b3af authored Sep 15, 2017 by Bjorn Andersson Committed by Ulf Hansson Oct 30, 2017

mmc: sdhci-msm: Enable delay circuit calibration clocks



The delay circuit used to support HS400 is calibrated based on two
additional clocks. When these clocks are not available and
FF_CLK_SW_RST_DIS is not set in CORE_HC_MODE, reset might fail. But on
some platforms this doesn't work properly and below dump can be seen in
the kernel log.

  mmc0: Reset 0x1 never completed.
  mmc0: sdhci: ============ SDHCI REGISTER DUMP ===========
  mmc0: sdhci: Sys addr:  0x00000000 | Version:  0x00001102
  mmc0: sdhci: Blk size:  0x00004000 | Blk cnt:  0x00000000
  mmc0: sdhci: Argument:  0x00000000 | Trn mode: 0x00000000
  mmc0: sdhci: Present:   0x01f80000 | Host ctl: 0x00000000
  mmc0: sdhci: Power:     0x00000000 | Blk gap:  0x00000000
  mmc0: sdhci: Wake-up:   0x00000000 | Clock:    0x00000002
  mmc0: sdhci: Timeout:   0x00000000 | Int stat: 0x00000000
  mmc0: sdhci: Int enab:  0x00000000 | Sig enab: 0x00000000
  mmc0: sdhci: AC12 err:  0x00000000 | Slot int: 0x00000000
  mmc0: sdhci: Caps:      0x742dc8b2 | Caps_1:   0x00008007
  mmc0: sdhci: Cmd:       0x00000000 | Max curr: 0x00000000
  mmc0: sdhci: Resp[0]:   0x00000000 | Resp[1]:  0x00000000
  mmc0: sdhci: Resp[2]:   0x00000000 | Resp[3]:  0x00000000
  mmc0: sdhci: Host ctl2: 0x00000000
  mmc0: sdhci: ============================================

Add support for the additional calibration clocks to allow these
platforms to be configured appropriately.

Cc: Venkat Gopalakrishnan <venkatg@codeaurora.org>
Cc: Ritesh Harjani <riteshh@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Tested-by: Jeremy McNicoll <jeremymc@redhat.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

parent e4bf91f6

Documentation/devicetree/bindings/mmc/sdhci-msm.txt

+2 −0

Original line number	Diff line number	Diff line
		@@ -18,6 +18,8 @@ Required properties:
		"core" - SDC MMC clock (MCLK) (required)
		"bus" - SDCC bus voter clock (optional)
		"xo" - TCXO clock (optional)
		"cal" - reference clock for RCLK delay calibration (optional)
		"sleep" - sleep clock for RCLK delay calibration (optional)

		Example:

drivers/mmc/host/sdhci-msm.c

+11 −1

Original line number	Diff line number	Diff line
		@@ -129,7 +129,7 @@ struct sdhci_msm_host {
		int pwr_irq; /* power irq */
		struct clk bus_clk; / SDHC bus voter clock */
		struct clk xo_clk; / TCXO clk needed for FLL feature of cm_dll*/
		struct clk_bulk_data bulk_clks[2]; /* core, iface clocks */
		struct clk_bulk_data bulk_clks[4]; /* core, iface, cal, sleep clocks */
		unsigned long clk_rate;
		struct mmc_host *mmc;
		bool use_14lpp_dll_reset;
		@@ -1184,6 +1184,16 @@ static int sdhci_msm_probe(struct platform_device *pdev)
		if (ret)
		dev_warn(&pdev->dev, "core clock boost failed\n");

		clk = devm_clk_get(&pdev->dev, "cal");
		if (IS_ERR(clk))
		clk = NULL;
		msm_host->bulk_clks[2].clk = clk;

		clk = devm_clk_get(&pdev->dev, "sleep");
		if (IS_ERR(clk))
		clk = NULL;
		msm_host->bulk_clks[3].clk = clk;

		ret = clk_bulk_prepare_enable(ARRAY_SIZE(msm_host->bulk_clks),
		msm_host->bulk_clks);
		if (ret)

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