[PATCH v2 1/3] mmc: atmel-mci: add device tree support
Thomas Abraham
thomas.abraham at linaro.org
Wed Mar 28 04:31:16 EDT 2012
On 28 March 2012 15:35, <ludovic.desroches at atmel.com> wrote:
> From: Ludovic Desroches <ludovic.desroches at atmel.com>
>
> Signed-off-by: Ludovic Desroches <ludovic.desroches at atmel.com>
> ---
> .../devicetree/bindings/mmc/atmel-hsmci.txt | 67 ++++++++++++++++
> drivers/mmc/host/atmel-mci.c | 80 ++++++++++++++++++++
> 2 files changed, 147 insertions(+), 0 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/mmc/atmel-hsmci.txt
>
> diff --git a/Documentation/devicetree/bindings/mmc/atmel-hsmci.txt b/Documentation/devicetree/bindings/mmc/atmel-hsmci.txt
> new file mode 100644
> index 0000000..bd21e52
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mmc/atmel-hsmci.txt
> @@ -0,0 +1,67 @@
> +* Atmel High Speed MultiMedia Card Interface
> +
> +This controller on atmel products provides an interface for MMC, SD and SDIO
> +types of memory cards.
> +
> +1) MCI node
> +
> +Required properties:
> +- compatible: no blank "atmel,hsmci"
> +- reg: should contain HSMCI registers location and length
> +- interrupts: should contain HSMCI interrupt number
> +- #address-cells: should be one. The cell is the slot id.
> +- #size-cells: should be zero.
> +- at least one slot node
> +
> +The node contains child nodes for each slot that the platform uses
> +
> +Example MCI node:
> +
> +mmc0: mmc at f0008000 {
> + compatible = "atmel,hsmci";
> + reg = <0xf0008000 0x600>;
> + interrupts = <12 4>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + [ child node definitions...]
> +};
> +
> +2) slot nodes
> +
> +Required properties:
> +- reg: should contain the slot id.
> +
> +Optional properties:
> +- bus-width: number of data lines connected to the controller
> +- cd-gpios: specify GPIOs for card detection
> +- cd-invert: invert the value of external card detect gpio line
> +- wp-gpios: specify GPIOs for write protection
There is a push for common bindings for sd/mmc and other card
controllers as suggested by Arnd here:
http://www.mail-archive.com/linux-mmc@vger.kernel.org/msg13421.html
> +
> +Example slot node:
> +
> +slot at 0 {
> + reg = <0>;
> + bus-width = <4>;
> + cd-gpios = <&pioD 15 0>
> + cd-invert;
> +};
> +
> +Example full MCI node:
> +mmc0: mmc at f0008000 {
> + compatible = "atmel,hsmci";
> + reg = <0xf0008000 0x600>;
> + interrupts = <12 4>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> + slot at 0 {
> + reg = <0>;
> + bus-width = <4>;
> + cd-gpios = <&pioD 15 0>
> + cd-invert;
> + };
> + slot at 1 {
> + reg = <1>;
> + bus-width = <4>;
> + };
> +};
> diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
> index b5693fd..b160be6 100644
> --- a/drivers/mmc/host/atmel-mci.c
> +++ b/drivers/mmc/host/atmel-mci.c
> @@ -19,6 +19,9 @@
> #include <linux/interrupt.h>
> #include <linux/ioport.h>
> #include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/of_gpio.h>
> #include <linux/platform_device.h>
> #include <linux/scatterlist.h>
> #include <linux/seq_file.h>
> @@ -477,6 +480,70 @@ err:
> dev_err(&mmc->class_dev, "failed to initialize debugfs for slot\n");
> }
>
> +#if defined(CONFIG_OF)
> +static const struct of_device_id atmci_dt_ids[] = {
> + { .compatible = "atmel,hsmci" },
> + { /* sentinel */ }
> +};
> +
> +MODULE_DEVICE_TABLE(of, atmci_dt_ids);
> +
> +static int __devinit atmci_of_init(struct platform_device *pdev)
> +{
> + struct device_node *np = pdev->dev.of_node;
> + struct device_node *cnp;
> + struct mci_platform_data *pdata;
> + unsigned int slot_id;
> + const __be32 *reg;
> +
> + if (!np)
> + return 0;
> +
> + pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
> + if (!pdata)
> + return -ENOMEM;
> +
> + for_each_child_of_node(np, cnp) {
> + reg = of_get_property(cnp, "reg", NULL);
> + if (!reg) {
> + dev_warn(&pdev->dev, "reg property is missing for %s\n",
> + cnp->full_name);
> + continue;
> + }
> +
> + slot_id = be32_to_cpu(reg[0]);
> +
> + if (slot_id > (ATMCI_MAX_NR_SLOTS-1)) {
> + dev_warn(&pdev->dev, "can't have more than %d slots\n",
> + ATMCI_MAX_NR_SLOTS);
> + break;
> + }
> +
> + if (of_property_read_u32(cnp, "bus-width",
> + &pdata->slot[slot_id].bus_width))
> + pdata->slot[slot_id].bus_width = 1;
> +
> + pdata->slot[slot_id].detect_pin =
> + of_get_named_gpio(cnp, "cd-gpios", 0);
> +
> + if (of_find_property(cnp, "cd-invert", NULL))
> + pdata->slot[slot_id].detect_is_active_high = true;
> +
> + pdata->slot[slot_id].wp_pin =
> + of_get_named_gpio(cnp, "wp-gpios", 0);
> + }
> +
> + pdev->dev.platform_data = pdata;
Assigning a pointer to pdev->dev.platform as done above is not
allowed. The pointer to pdata obtained from dt should be stored as
part of the driver's private data and used. (I used to do the same
mistake until I learnt this lesson learnt from Grant).
> +
> + return 0;
> +}
> +#else /* CONFIG_OF */
> +static inline int atmci_of_init(struct platform_device *dev)
> +{
> + return 0;
> +}
> +#endif
> +
> static inline unsigned int atmci_ns_to_clocks(struct atmel_mci *host,
> unsigned int ns)
> {
> @@ -1847,6 +1914,13 @@ static int __init atmci_init_slot(struct atmel_mci *host,
> slot->sdc_reg = sdc_reg;
> slot->sdio_irq = sdio_irq;
>
> + dev_dbg(&mmc->class_dev,
> + "slot[%u]: bus_width=%u, detect_pin=%d, "
> + "detect_is_active_high=%s, wp_pin=%d\n",
> + id, slot_data->bus_width, slot_data->detect_pin,
> + slot_data->detect_is_active_high ? "true" : "false",
> + slot_data->wp_pin);
> +
> mmc->ops = &atmci_ops;
> mmc->f_min = DIV_ROUND_UP(host->bus_hz, 512);
> mmc->f_max = host->bus_hz / 2;
> @@ -2047,6 +2121,11 @@ static int __init atmci_probe(struct platform_device *pdev)
> regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> if (!regs)
> return -ENXIO;
> +
> + ret = atmci_of_init(pdev);
> + if (ret)
> + return ret;
> +
> pdata = pdev->dev.platform_data;
> if (!pdata)
> return -ENXIO;
> @@ -2242,6 +2321,7 @@ static struct platform_driver atmci_driver = {
> .driver = {
> .name = "atmel_mci",
> .pm = ATMCI_PM_OPS,
> + .of_match_table = of_match_ptr(atmci_dt_ids),
> },
> };
>
> --
> 1.7.5.4
Thanks,
Thomas.
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