Re: [PATCH v2 2/3] mmc: davinci_mmc: add DT support
From: Mark Rutland <mark.rutland@arm.com>
Date: 2013-02-07 10:47:06
Also in:
linux-arm-kernel, linux-mmc, lkml
Hello, I have a couple of comments on the dt bindings and the way it's parsed. On Thu, Feb 07, 2013 at 07:57:04AM +0000, Manjunathappa, Prakash wrote:
quoted hunk ↗ jump to hunk
Adds device tree support for davinci_mmc. Also add binding documentation. Tested in non-dma PIO mode and without GPIO card_detect/write_protect option because of dependencies on EDMA and GPIO module DT support. Signed-off-by: Manjunathappa, Prakash <redacted> Cc: linux-mmc@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Cc: davinci-linux-open-source@linux.davincidsp.com Cc: devicetree-discuss@lists.ozlabs.org Cc: cjb@laptop.org Cc: Sekhar Nori <redacted> Cc: mporter@ti.com --- Since v1: Modified DT parse function to take default values and accomodate controller version in compatible field. .../devicetree/bindings/mmc/davinci_mmc.txt | 30 ++++++++ drivers/mmc/host/davinci_mmc.c | 70 +++++++++++++++++++- 2 files changed, 99 insertions(+), 1 deletions(-) create mode 100644 Documentation/devicetree/bindings/mmc/davinci_mmc.txtdiff --git a/Documentation/devicetree/bindings/mmc/davinci_mmc.txt b/Documentation/devicetree/bindings/mmc/davinci_mmc.txt new file mode 100644 index 0000000..6717ab1 --- /dev/null +++ b/Documentation/devicetree/bindings/mmc/davinci_mmc.txt@@ -0,0 +1,30 @@ +* TI Highspeed MMC host controller for DaVinci + +The Highspeed MMC Host Controller on TI DaVinci family +provides an interface for MMC, SD and SDIO types of memory cards. + +This file documents the properties used by the davinci_mmc driver. + +Required properties: +- compatible: + Should be "ti,davinci-mmc-da830": for da830, da850, dm365 + Should be "ti,davinci-mmc-dm355": for dm355, dm644x + +Optional properties: +- bus-width: Number of data lines, can be <4>, or <8>, default <1> +- max-frequency: Maximum operating clock frequency, default 25MHz. +- mmc-cap-mmc-highspeed: Indicates support for MMC in high speed mode +- mmc-cap-sd-highspeed: Indicates support for SD in high speed mode
I thought the last two were derivable from max-frequency? https://lkml.org/lkml/2012/10/15/231 [...]
+static struct davinci_mmc_config
+ *mmc_parse_pdata(struct platform_device *pdev)
{
+ struct device_node *np;
struct davinci_mmc_config *pdata = pdev->dev.platform_data;
+ const struct of_device_id *match =
+ of_match_device(of_match_ptr(davinci_mmc_dt_ids), &pdev->dev);
+ u32 data;
+
+ np = pdev->dev.of_node;
+ if (!np)
+ return pdata;
+
+ pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+ if (!pdata) {
+ dev_err(&pdev->dev, "Failed to allocate memory for struct davinci_mmc_config\n");
+ goto nodata;
+ }
+
+ if (match->data)
+ pdata->version = (u8)((int)match->data);
+
+ of_property_read_u32(np, "max-frequency", &pdata->max_freq);
+ if (!pdata->max_freq)
+ dev_info(&pdev->dev, "'max-frequency' property not specified, defaulting to 25MHz\n");
+
+ if (of_get_property(np, "mmc-cap-mmc-highspeed", NULL))
+ pdata->caps |= MMC_CAP_MMC_HIGHSPEED;
+ if (of_get_property(np, "mmc-cap-sd-highspeed", NULL))
+ pdata->caps |= MMC_CAP_SD_HIGHSPEED;If these aren't derivable from max-frequency, you could use of_property_read_bool to make this clearer.
+
+ of_property_read_u32(np, "bus-width", &data);
+ switch (data) {
+ case 0:Judging by the binding doc, should this be 1 rather than 0?
+ case 4:
+ case 8:
+ pdata->wires = data;
+ break;
+ default:
+ pdata->wires = 1;
+ dev_info(&pdev->dev, "Unsupported buswidth, defaulting to 1 bit\n");
+ }
+nodata:
+ return pdata;
+}
+
+static int __init davinci_mmcsd_probe(struct platform_device *pdev)
+{
+ struct davinci_mmc_config *pdata = NULL;
struct mmc_davinci_host *host = NULL;
struct mmc_host *mmc = NULL;
struct resource *r, *mem = NULL;
int ret = 0, irq = 0;
size_t mem_size;
+ pdata = mmc_parse_pdata(pdev);
+ if (pdata == NULL) {
+ dev_err(&pdev->dev, "Can not get platform data\n");
+ return -ENOENT;
+ }
+
/* REVISIT: when we're fully converted, fail if pdata is NULL */This comment can presumably disappear judging by the lines above? [...] Thanks, Mark.