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Message-ID: <CAAAP30FxjUzwuifRJW_NP5Y=o9DXHD5TcX_AOd_BSt25_TxV6g@mail.gmail.com>
Date: Tue, 21 Aug 2012 13:12:54 -0300
From: Alexandre Pereira da Silva <aletes.xgr@...il.com>
To: Roland Stigge <stigge@...com.de>
Cc: linus.walleij@...aro.org, broonie@...nsource.wolfsonmicro.com,
grant.likely@...retlab.ca, rob.herring@...xeda.com,
rob@...dley.net, devicetree-discuss@...ts.ozlabs.org,
linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org,
spi-devel-general@...ts.sourceforge.net,
gabriel.fernandez@...ricsson.com, lee.jones@...aro.org,
viresh.kumar@...aro.org, sachin.verma@...co
Subject: Re: [PATCH v5 2/2] spi/pl022: Add devicetree support
On Tue, Aug 21, 2012 at 1:01 PM, Roland Stigge <stigge@...com.de> wrote:
> This patch adds device tree support to the spi-pl022 driver.
>
> Based on the initial patch by Alexandre Pereira da Silva <aletes.xgr@...il.com>
>
> Signed-off-by: Roland Stigge <stigge@...com.de>
Acked-By: Alexandre Pereira da Silva <aletes.xgr@...il.com>
> ---
>
> Documentation/devicetree/bindings/spi/spi_pl022.txt | 15 +++
> drivers/spi/spi-pl022.c | 79 +++++++++++++++++---
> 2 files changed, 85 insertions(+), 9 deletions(-)
>
> --- linux-2.6.orig/Documentation/devicetree/bindings/spi/spi_pl022.txt
> +++ linux-2.6/Documentation/devicetree/bindings/spi/spi_pl022.txt
> @@ -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
> +
> --- linux-2.6.orig/drivers/spi/spi-pl022.c
> +++ linux-2.6/drivers/spi/spi-pl022.c
> @@ -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 pl
> 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
> 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;
> +
> + 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, co
> 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, co
> 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;
> @@ -2037,17 +2073,41 @@ pl022_probe(struct amba_device *adev, co
> * 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->chipselect[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->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);
> + }
> + }
> + }
>
> /*
> * Supports mode 0-3, loopback, and active low CS. Transfers are
> @@ -2157,6 +2217,7 @@ pl022_probe(struct amba_device *adev, co
> err_no_ioremap:
> amba_release_regions(adev);
> err_no_ioregion:
> + err_no_gpio:
> spi_master_put(master);
> err_no_master:
> err_no_pdata:
--
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