Re: [PATCH RESEND v4] spi/pl022: add devicetree support

From: Linus Walleij
Date: Mon Aug 20 2012 - 11:02:41 EST

Next message: Oleg Nesterov: "Re: lockdep trace from posix timers"
Previous message: Stephen Warren: "Re: [PATCH] regulator: max8907: Properly set pmic pointer in max8907_regulator_remove()"
In reply to: Rob Herring: "Re: [PATCH RESEND v4] spi/pl022: add devicetree support"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

(Currently make sure to include Mark Brown (see To: line) on all SPI patches,
as he's collecting them.)

On Mon, Aug 20, 2012 at 1:39 PM, Alexandre Pereira da Silva
<aletes.xgr@xxxxxxxxx> wrote:

> Add the chipselect array and cur_cs properties to pl022 main structure

OK...

> diff --git a/Documentation/devicetree/bindings/spi/spi_pl022.txt b/Documentation/devicetree/bindings/spi/spi_pl022.txt

This looks fine to me.

> +#include <linux/gpio.h>
> +#include <linux/of_gpio.h>

Hm, it looks like two changes are embedded in this patch.

>
> /*
> * This macro is used to define some register default values.
> @@ -389,6 +391,8 @@ struct pl022 {
> char *dummypage;
> bool dma_running;
> #endif
> + int cur_cs;
> + int chipselect[0];
> };

You forgot to add kerneldoc for these two. Please add!

int chipselect[0] really? isn't int *chipselect what you really want
to store in there?

> + if (gpio_is_valid(pl022->cur_cs))
> + gpio_set_value(pl022->cur_cs, command);
> + else
> + pl022->cur_chip->cs_control(command);
> +}

So it seems like this should be two patches:

- One adding pl022->cur_cs and the ability for the driver to control
the chip select directly from msg->spi->chip_select
Make sure it is possible to populate pl022->chipselect also
from platform data since many people are using that
still.

- Another patch adding device tree and that stuff.

So please split it in two.

> - pl022->cur_chip->cs_control(SSP_CHIP_DESELECT);
> + pl022_cs_control(pl022, SSP_CHIP_DESELECT);

All these are OK and go in the first patch.

> + pl022->cur_cs = pl022->chipselect[msg->spi->chip_select];

Goes into the first patch...

> @@ -1761,12 +1772,14 @@ static const struct pl022_config_chip pl022_default_chip_info = {
> static int pl022_setup(struct spi_device *spi)
> {
> struct pl022_config_chip const *chip_info;
> + struct pl022_config_chip chip_info_dt;

Goes into second patch.

> struct chip_data *chip;
> struct ssp_clock_params clk_freq = { .cpsdvsr = 0, .scr = 0};
> int status = 0;
> struct pl022 *pl022 = spi_master_get_devdata(spi->master);
> unsigned int bits = spi->bits_per_word;
> u32 tmp;
> + struct device_node *np = spi->dev.of_node;

Does this compile if CONFIG_OF is not selected?

I have seen other drivers have #ifdef CONFIG_OF around these
things.

Make sure you test-compile without DT.

> @@ -1789,10 +1802,36 @@ static int pl022_setup(struct spi_device *spi)
> chip_info = spi->controller_data;
>
> if (chip_info == NULL) {
> - chip_info = &pl022_default_chip_info;
> - /* spi_board_info.controller_data not is supplied */
> - dev_dbg(&spi->dev,
> - "using default controller_data settings\n");
> + if (np) {
> + chip_info_dt = pl022_default_chip_info;
> +
> + of_property_read_u32(np, "pl022,hierarchy",
> + &chip_info_dt.hierarchy);
> + of_property_read_u32(np, "pl022,interface",
> + &chip_info_dt.iface);
> + chip_info_dt.slave_tx_disable =
> + of_property_read_bool(np,
> + "pl022,slave-tx-disable");
> + of_property_read_u32(np, "pl022,com-mode",
> + &chip_info_dt.com_mode);
> + of_property_read_u32(np, "pl022,rx-level-trig",
> + &chip_info_dt.rx_lev_trig);
> + of_property_read_u32(np, "pl022,tx-level-trig",
> + &chip_info_dt.tx_lev_trig);
> + of_property_read_u32(np, "pl022,ctrl-len",
> + &chip_info_dt.ctrl_len);
> + of_property_read_u32(np, "pl022,wait-state",
> + &chip_info_dt.wait_state);
> + of_property_read_u32(np, "pl022,duplex",
> + &chip_info_dt.duplex);
> +
> + chip_info = &chip_info_dt;
> + } else {
> + chip_info = &pl022_default_chip_info;
> + /* spi_board_info.controller_data not is supplied */
> + dev_dbg(&spi->dev,
> + "using default controller_data settings\n");
> + }

Goes into second patch.

> @@ -1835,8 +1874,9 @@ static int pl022_setup(struct spi_device *spi)
> chip->xfer_type = chip_info->com_mode;
> if (!chip_info->cs_control) {
> chip->cs_control = null_cs_control;
> - dev_warn(&spi->dev,
> - "chip select function is NULL for this chip\n");
> + if (!gpio_is_valid(pl022->chipselect[spi->chip_select]))
> + dev_warn(&spi->dev,
> + "chip select function is NULL for this chip\n");
> } else
> chip->cs_control = chip_info->cs_control;

Goes into first patch.

> @@ -1988,7 +2028,8 @@ pl022_probe(struct amba_device *adev, const struct amba_id *id)
> struct pl022_ssp_controller *platform_info = adev->dev.platform_data;
> struct spi_master *master;
> struct pl022 *pl022 = NULL; /*Data for this driver */
> - int status = 0;
> + struct device_node *np = adev->dev.of_node;

Does this compile without CONFIG_OF?
(Second patch)

> + int status = 0, i, num_cs;
>
> dev_info(&adev->dev,
> "ARM PL022 driver, device ID: 0x%08x\n", adev->periphid);
> @@ -1998,8 +2039,14 @@ pl022_probe(struct amba_device *adev, const struct amba_id *id)
> goto err_no_pdata;
> }
>
> + num_cs = platform_info->num_chipselect;
> + if (IS_ENABLED(CONFIG_OF))
> + of_property_read_u32(np, "pl022,num-chipselects", &num_cs);
> +
> +

Shouldn't it be the other way around: platform data overrides
DT data. Attempt DT and if platform_info->num_chipselect
!= 0 let it override.

(Second patch.)

> /* Allocate master with space for data */
> - master = spi_alloc_master(dev, sizeof(struct pl022));
> + master = spi_alloc_master(dev,
> + sizeof(struct pl022) + sizeof(int) * num_cs);

First patch.

> if (master == NULL) {
> dev_err(&adev->dev, "probe - cannot alloc SPI master\n");
> status = -ENOMEM;
> @@ -2017,13 +2064,41 @@ pl022_probe(struct amba_device *adev, const struct amba_id *id)
> * on this board
> */
> master->bus_num = platform_info->bus_id;
> - master->num_chipselect = platform_info->num_chipselect;
> + master->num_chipselect = num_cs;

OK first patch.

> master->cleanup = pl022_cleanup;
> master->setup = pl022_setup;
> master->prepare_transfer_hardware = pl022_prepare_transfer_hardware;
> master->transfer_one_message = pl022_transfer_one_message;
> master->unprepare_transfer_hardware = pl022_unprepare_transfer_hardware;
> master->rt = platform_info->rt;
> + master->dev.of_node = dev->of_node;

Does this compile without CONFIG_OF?
Second patch.

> + if (IS_ENABLED(CONFIG_OF)) {
> + for (i = 0; i < num_cs; i++) {
> + int cs_gpio = of_get_named_gpio(np, "cs-gpios", i);
> +
> + if (cs_gpio == -EPROBE_DEFER) {
> + status = -EPROBE_DEFER;
> + goto err_no_gpio;
> + }
> +
> + pl022->chipselect[i] = cs_gpio;
> +
> + if (gpio_is_valid(cs_gpio)) {
> + if (gpio_request(cs_gpio, "ssp-pl022"))
> + dev_err(&adev->dev,
> + "could not request %d gpio\n",
> + cs_gpio);
> + else if (gpio_direction_output(cs_gpio, 1))
> + dev_err(&adev->dev,
> + "could set gpio %d as output\n",
> + cs_gpio);
> + }
> + }
> + } else {
> + for (i = 0; i < num_cs; i++)
> + pl022->chipselect[i] = -EINVAL;

Why? Instead, add a int *chipselects; field to the struct pl022_ssp_controller
platform data in include/linux/amba/pl022.h and copy it from there if
num_chipselects in the same data != 0.

(First patch.)

Yours,
Linus Walleij
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

Next message: Oleg Nesterov: "Re: lockdep trace from posix timers"
Previous message: Stephen Warren: "Re: [PATCH] regulator: max8907: Properly set pmic pointer in max8907_regulator_remove()"
In reply to: Rob Herring: "Re: [PATCH RESEND v4] spi/pl022: add devicetree support"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]