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Commit 6d3952a7 authored by Roland Stigge's avatar Roland Stigge Committed by Mark Brown
Browse files

spi/pl022: Add devicetree support 



This patch adds device tree support to the spi-pl022 driver.

Based on the initial patch by Alexandre Pereira da Silva <aletes.xgr@gmail.com>

Signed-off-by: default avatarRoland Stigge <stigge@antcom.de>
Acked-by: default avatarAlexandre Pereira da Silva <aletes.xgr@gmail.com>
Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarMark Brown <broonie@opensource.wolfsonmicro.com>
parent f6f46de1

Documentation/devicetree/bindings/spi/spi_pl022.txt

+15 −0
Original line number Diff line number Diff line
@@ -6,7 +6,22 @@ Required properties: 
- interrupts : Should contain SPI controller interrupt



Optional properties:

- num-cs : total number of chipselects

- cs-gpios : should specify GPIOs used for chipselects.

  The gpios will be referred to as reg = <index> in the SPI child nodes.

  If unspecified, a single SPI device without a chip select can be used.



SPI slave nodes must be children of the SPI master node and can

contain the following properties.



- pl022,interface : interface type:

	0: SPI

	1: Texas Instruments Synchronous Serial Frame Format

	2: Microwire (Half Duplex)

- pl022,com-mode : polling, interrupt or dma

- pl022,rx-level-trig : Rx FIFO watermark level

- pl022,tx-level-trig : Tx FIFO watermark level

- pl022,ctrl-len : Microwire interface: Control length

- pl022,wait-state : Microwire interface: Wait state

- pl022,duplex : Microwire interface: Full/Half duplex

drivers/spi/spi-pl022.c

+70 −9
Original line number Diff line number Diff line
@@ -41,6 +41,7 @@ 
#include <linux/scatterlist.h>

#include <linux/pm_runtime.h>

#include <linux/gpio.h>

#include <linux/of_gpio.h>



/*

 * This macro is used to define some register default values.
@@ -1778,12 +1779,14 @@ 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;

	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;



	if (!spi->max_speed_hz)

		return -EINVAL;
@@ -1806,10 +1809,32 @@ static int pl022_setup(struct spi_device *spi) 
	chip_info = spi->controller_data;



	if (chip_info == NULL) {

		if (np) {

			chip_info_dt = pl022_default_chip_info;



			chip_info_dt.hierarchy = SSP_MASTER;

			of_property_read_u32(np, "pl022,interface",

				&chip_info_dt.iface);

			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");

		}

	} else

		dev_dbg(&spi->dev,

			"using user supplied controller_data settings\n");
@@ -2006,7 +2031,8 @@ 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, i;

	struct device_node *np = adev->dev.of_node;

	int status = 0, i, num_cs;



	dev_info(&adev->dev,

		 "ARM PL022 driver, device ID: 0x%08x\n", adev->periphid);
@@ -2016,9 +2042,19 @@ pl022_probe(struct amba_device *adev, const struct amba_id *id) 
		goto err_no_pdata;

	}



	if (platform_info->num_chipselect) {

		num_cs = platform_info->num_chipselect;

	} else if (IS_ENABLED(CONFIG_OF)) {

		of_property_read_u32(np, "num-cs", &num_cs);

	} else {

		dev_err(&adev->dev, "probe: no chip select defined\n");

		status = -ENODEV;

		goto err_no_pdata;

	}



	/* Allocate master with space for data */

	master = spi_alloc_master(dev, sizeof(struct pl022) + sizeof(int) *

				  platform_info->num_chipselect);

				  num_cs);

	if (master == NULL) {

		dev_err(&adev->dev, "probe - cannot alloc SPI master\n");

		status = -ENOMEM;
@@ -2038,17 +2074,41 @@ 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;

	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;



	if (platform_info->num_chipselect && platform_info->chipselects)

		for (i = 0; i < platform_info->num_chipselect; i++)

	if (platform_info->num_chipselect && platform_info->chipselects) {

		for (i = 0; i < num_cs; i++)

			pl022->chipselects[i] = platform_info->chipselects[i];

	} else 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->chipselects[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);

			}

		}

	}



	/*

	 * Supports mode 0-3, loopback, and active low CS. Transfers are
@@ -2158,6 +2218,7 @@ pl022_probe(struct amba_device *adev, const struct amba_id *id) 
 err_no_ioremap:

	amba_release_regions(adev);

 err_no_ioregion:

 err_no_gpio:

	spi_master_put(master);

 err_no_master:

 err_no_pdata: