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Subject[PATCH v5 2/2] spi/pl022: Add devicetree support
Date
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: Roland Stigge <stigge@antcom.de>
---

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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