Re: [PATCH 2/3] mmc: sdhci-of-at91: introduce driver for the Atmel SDMMC
From: Arnd Bergmann <arnd@arndb.de>
Date: 2015-07-05 09:40:25
Also in:
linux-mmc, lkml
On Friday 03 July 2015 16:17:16 Ludovic Desroches wrote:
quoted hunk ↗ jump to hunk
Introduce driver for he Atmel SDMMC available on sama5d2. It is a sdhci compliant controller. Signed-off-by: Ludovic Desroches <redacted> --- .../devicetree/bindings/mmc/sdhci-atmel.txt | 21 +++ drivers/mmc/host/Kconfig | 8 + drivers/mmc/host/Makefile | 1 + drivers/mmc/host/sdhci-of-at91.c | 188 +++++++++++++++++++++ 4 files changed, 218 insertions(+) create mode 100644 Documentation/devicetree/bindings/mmc/sdhci-atmel.txt create mode 100644 drivers/mmc/host/sdhci-of-at91.cdiff --git a/Documentation/devicetree/bindings/mmc/sdhci-atmel.txt b/Documentation/devicetree/bindings/mmc/sdhci-atmel.txt new file mode 100644 index 0000000..1b662d7 --- /dev/null +++ b/Documentation/devicetree/bindings/mmc/sdhci-atmel.txt@@ -0,0 +1,21 @@ +* Atmel SDHCI controller + +This file documents the differences between the core properties in +Documentation/devicetree/bindings/mmc/mmc.txt and the properties used by the +sdhci-of-at91 driver. + +Required properties: +- compatible: Must be "atmel,sama5d2-sdhci". +- clocks: Phandlers to the clocks. +- clock-names: Must be "hclock", "multclk", "baseclk"; +
Are you sure that these are all new clocks that are unrelated to the "core", "mmc", and "iface" clocks that are used in other drivers?
+
+ priv->mainck = devm_clk_get(&pdev->dev, "baseclk");
+ if (IS_ERR(priv->mainck)) {
+ dev_err(&pdev->dev, "failed to get baseclk\n");
+ return PTR_ERR(priv->mainck);
+ }
+
+ priv->hclock = devm_clk_get(&pdev->dev, "hclock");
+ if (IS_ERR(priv->hclock)) {
+ dev_err(&pdev->dev, "failed to get hclock\n");
+ return PTR_ERR(priv->hclock);
+ }
+
+ priv->gck = devm_clk_get(&pdev->dev, "multclk");
+ if (IS_ERR(priv->gck)) {
+ dev_err(&pdev->dev, "failed to get multclk\n");
+ return PTR_ERR(priv->gck);
+ }
+
+ host = sdhci_pltfm_init(pdev, soc_data, 0);
+ if (IS_ERR(host))
+ return PTR_ERR(host);
+
+ /*
+ * The mult clock is provided by as a generated clock by the PMC
+ * controller. In order to set the rate of gck, we have to get the
+ * base clock rate and the clock mult from capabilities.
+ */
+ clk_prepare_enable(priv->hclock);
+ caps0 = readl(host->ioaddr + SDHCI_CAPABILITIES);
+ caps1 = readl(host->ioaddr + SDHCI_CAPABILITIES_1);
+ clk_base = (caps0 & SDHCI_CLOCK_V3_BASE_MASK) >> SDHCI_CLOCK_BASE_SHIFT;
+ clk_mul = (caps1 & SDHCI_CLOCK_MUL_MASK) >> SDHCI_CLOCK_MUL_SHIFT;
+ gck_rate = clk_base * 1000000 * (clk_mul + 1);
+ ret = clk_set_rate(priv->gck, gck_rate);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to set gck");
+ goto hclock_disable_unprepare;
+ return -EINVAL;
+ }Could this be shared with other drivers? Arnd