[PATCH v4 6/6] spi: s3c64xx: add device tree support
Thomas Abraham
thomas.abraham at linaro.org
Wed Jul 11 00:27:39 EST 2012
Add support for device based discovery.
Signed-off-by: Thomas Abraham <thomas.abraham at linaro.org>
Acked-by: Jaswinder Singh <jaswinder.singh at linaro.org>
Acked-by: Grant Likely <grant.likely at secretlab.ca>
---
.../devicetree/bindings/spi/spi-samsung.txt | 113 ++++++++
drivers/spi/spi-s3c64xx.c | 277 +++++++++++++++++---
2 files changed, 358 insertions(+), 32 deletions(-)
create mode 100644 Documentation/devicetree/bindings/spi/spi-samsung.txt
diff --git a/Documentation/devicetree/bindings/spi/spi-samsung.txt b/Documentation/devicetree/bindings/spi/spi-samsung.txt
new file mode 100644
index 0000000..59bfc4f
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/spi-samsung.txt
@@ -0,0 +1,113 @@
+* Samsung SPI Controller
+
+The Samsung SPI controller is used to interface with various devices such as flash
+and display controllers using the SPI communication interface.
+
+Required SoC Specific Properties:
+
+- compatible: should be one of the following.
+ - samsung,s3c2443-spi: for s3c2443, s3c2416 and s3c2450 platforms
+ - samsung,s3c6410-spi: for s3c6410 platforms
+ - samsung,s5p6440-spi: for s5p6440 and s5p6450 platforms
+ - samsung,s5pv210-spi: for s5pv210 and s5pc110 platforms
+ - samsung,exynos4210-spi: for exynos4 and exynos5 platforms
+
+- reg: physical base address of the controller and length of memory mapped
+ region.
+
+- interrupts: The interrupt number to the cpu. The interrupt specifier format
+ depends on the interrupt controller.
+
+- tx-dma-channel: The dma channel specifier for tx operations. The format of
+ the dma specifier depends on the dma controller.
+
+- rx-dma-channel: The dma channel specifier for rx operations. The format of
+ the dma specifier depends on the dma controller.
+
+Required Board Specific Properties:
+
+- #address-cells: should be 1.
+- #size-cells: should be 0.
+- gpios: The gpio specifier for clock, mosi and miso interface lines (in the
+ order specified). The format of the gpio specifier depends on the gpio
+ controller.
+
+Optional Board Specific Properties:
+
+- samsung,spi-src-clk: If the spi controller includes a internal clock mux to
+ select the clock source for the spi bus clock, this property can be used to
+ indicate the clock to be used for driving the spi bus clock. If not specified,
+ the clock number 0 is used as default.
+
+- num-cs: Specifies the number of chip select lines supported. If
+ not specified, the default number of chip select lines is set to 1.
+
+SPI Controller specific data in SPI slave nodes:
+
+- The spi slave nodes should provide the following information which is required
+ by the spi controller.
+
+ - cs-gpio: A gpio specifier that specifies the gpio line used as
+ the slave select line by the spi controller. The format of the gpio
+ specifier depends on the gpio controller.
+
+ - samsung,spi-feedback-delay: The sampling phase shift to be applied on the
+ miso line (to account for any lag in the miso line). The following are the
+ valid values.
+
+ - 0: No phase shift.
+ - 1: 90 degree phase shift sampling.
+ - 2: 180 degree phase shift sampling.
+ - 3: 270 degree phase shift sampling.
+
+Aliases:
+
+- All the SPI controller nodes should be represented in the aliases node using
+ the following format 'spi{n}' where n is a unique number for the alias.
+
+
+Example:
+
+- SoC Specific Portion:
+
+ spi_0: spi at 12d20000 {
+ compatible = "samsung,exynos4210-spi";
+ reg = <0x12d20000 0x100>;
+ interrupts = <0 66 0>;
+ tx-dma-channel = <&pdma0 5>;
+ rx-dma-channel = <&pdma0 4>;
+ };
+
+- Board Specific Portion:
+
+ spi_0: spi at 12d20000 {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ gpios = <&gpa2 4 2 3 0>,
+ <&gpa2 6 2 3 0>,
+ <&gpa2 7 2 3 0>;
+
+ w25q80bw at 0 {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ compatible = "w25x80";
+ reg = <0>;
+ spi-max-frequency = <10000>;
+
+ controller-data {
+ cs-gpio = <&gpa2 5 1 0 3>;
+ samsung,spi-feedback-delay = <0>;
+ };
+
+ partition at 0 {
+ label = "U-Boot";
+ reg = <0x0 0x40000>;
+ read-only;
+ };
+
+ partition at 40000 {
+ label = "Kernel";
+ reg = <0x40000 0xc0000>;
+ };
+ };
+ };
diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 068600d..e4fb8d2 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -28,6 +28,8 @@
#include <linux/pm_runtime.h>
#include <linux/spi/spi.h>
#include <linux/gpio.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
#include <mach/dma.h>
#include <plat/s3c64xx-spi.h>
@@ -137,6 +139,7 @@ struct s3c64xx_spi_dma_data {
unsigned ch;
enum dma_data_direction direction;
enum dma_ch dmach;
+ struct property *dma_prop;
};
/**
@@ -201,6 +204,7 @@ struct s3c64xx_spi_driver_data {
struct samsung_dma_ops *ops;
struct s3c64xx_spi_port_config *port_conf;
unsigned int port_id;
+ unsigned long gpios[4];
};
static struct s3c2410_dma_client s3c64xx_spi_dma_client = {
@@ -326,7 +330,9 @@ static int acquire_dma(struct s3c64xx_spi_driver_data *sdd)
req.cap = DMA_SLAVE;
req.client = &s3c64xx_spi_dma_client;
+ req.dt_dmach_prop = sdd->rx_dma.dma_prop;
sdd->rx_dma.ch = sdd->ops->request(sdd->rx_dma.dmach, &req);
+ req.dt_dmach_prop = sdd->tx_dma.dma_prop;
sdd->tx_dma.ch = sdd->ops->request(sdd->tx_dma.dmach, &req);
return 1;
@@ -819,6 +825,50 @@ static int s3c64xx_spi_unprepare_transfer(struct spi_master *spi)
return 0;
}
+static struct s3c64xx_spi_csinfo *s3c64xx_get_slave_ctrldata(
+ struct s3c64xx_spi_driver_data *sdd,
+ struct spi_device *spi)
+{
+ struct s3c64xx_spi_csinfo *cs;
+ struct device_node *slave_np, *data_np;
+ u32 fb_delay = 0;
+
+ slave_np = spi->dev.of_node;
+ if (!slave_np) {
+ dev_err(&spi->dev, "device node not found\n");
+ return ERR_PTR(-EINVAL);
+ }
+
+ for_each_child_of_node(slave_np, data_np)
+ if (!strcmp(data_np->name, "controller-data"))
+ break;
+ if (!data_np) {
+ dev_err(&spi->dev, "child node 'controller-data' not found\n");
+ return ERR_PTR(-EINVAL);
+ }
+
+ cs = devm_kzalloc(&sdd->pdev->dev, sizeof(*cs), GFP_KERNEL);
+ if (!cs) {
+ dev_err(&spi->dev, "could not allocate memory for controller"
+ " data\n");
+ return ERR_PTR(-ENOMEM);
+ }
+
+ cs->line = of_get_named_gpio(data_np, "cs-gpio", 0);
+ if (!gpio_is_valid(cs->line)) {
+ dev_err(&spi->dev, "chip select gpio is invalid\n");
+ return ERR_PTR(-EINVAL);
+ }
+ if (devm_gpio_request(&sdd->pdev->dev, cs->line, "spi-cs")) {
+ dev_err(&spi->dev, "gpio [%d] request failed\n", cs->line);
+ return ERR_PTR(-EBUSY);
+ }
+
+ of_property_read_u32(data_np, "samsung,spi-feedback-delay", &fb_delay);
+ cs->fb_delay = fb_delay;
+ return cs;
+}
+
/*
* Here we only check the validity of requested configuration
* and save the configuration in a local data-structure.
@@ -834,12 +884,17 @@ static int s3c64xx_spi_setup(struct spi_device *spi)
unsigned long flags;
int err = 0;
- if (cs == NULL) {
+ sdd = spi_master_get_devdata(spi->master);
+ if (!cs && spi->dev.of_node) {
+ cs = s3c64xx_get_slave_ctrldata(sdd, spi);
+ spi->controller_data = cs;
+ }
+
+ if (IS_ERR_OR_NULL(cs)) {
dev_err(&spi->dev, "No CS for SPI(%d)\n", spi->chip_select);
return -ENODEV;
}
- sdd = spi_master_get_devdata(spi->master);
sci = sdd->cntrlr_info;
spin_lock_irqsave(&sdd->lock, flags);
@@ -970,49 +1025,166 @@ static void s3c64xx_spi_hwinit(struct s3c64xx_spi_driver_data *sdd, int channel)
flush_fifo(sdd);
}
+static int __devinit s3c64xx_spi_get_dmares(
+ struct s3c64xx_spi_driver_data *sdd, bool tx)
+{
+ struct platform_device *pdev = sdd->pdev;
+ struct s3c64xx_spi_dma_data *dma_data;
+ struct property *prop;
+ struct resource *res;
+ char prop_name[15], *chan_str;
+
+ if (tx) {
+ dma_data = &sdd->tx_dma;
+ dma_data->direction = DMA_TO_DEVICE;
+ chan_str = "tx";
+ } else {
+ dma_data = &sdd->rx_dma;
+ dma_data->direction = DMA_FROM_DEVICE;
+ chan_str = "rx";
+ }
+
+ if (!sdd->pdev->dev.of_node) {
+ res = platform_get_resource(pdev, IORESOURCE_DMA, tx ? 0 : 1);
+ if (!res) {
+ dev_err(&pdev->dev, "Unable to get SPI-%s dma "
+ "resource\n", chan_str);
+ return -ENXIO;
+ }
+ dma_data->dmach = res->start;
+ return 0;
+ }
+
+ sprintf(prop_name, "%s-dma-channel", chan_str);
+ prop = of_find_property(pdev->dev.of_node, prop_name, NULL);
+ if (!prop) {
+ dev_err(&pdev->dev, "%s dma channel property not specified\n",
+ chan_str);
+ return -ENXIO;
+ }
+
+ dma_data->dmach = DMACH_DT_PROP;
+ dma_data->dma_prop = prop;
+ return 0;
+}
+
+#ifdef CONFIG_OF
+static int s3c64xx_spi_parse_dt_gpio(struct s3c64xx_spi_driver_data *sdd)
+{
+ struct device *dev = &sdd->pdev->dev;
+ int idx, gpio, ret;
+
+ /* find gpios for mosi, miso and clock lines */
+ for (idx = 0; idx < 3; idx++) {
+ gpio = of_get_gpio(dev->of_node, idx);
+ if (!gpio_is_valid(gpio)) {
+ dev_err(dev, "invalid gpio[%d]: %d\n", idx, gpio);
+ goto free_gpio;
+ }
+
+ ret = gpio_request(gpio, "spi-bus");
+ if (ret) {
+ dev_err(dev, "gpio [%d] request failed\n", gpio);
+ goto free_gpio;
+ }
+ }
+ return 0;
+
+free_gpio:
+ while (--idx >= 0)
+ gpio_free(sdd->gpios[idx]);
+ return -EINVAL;
+}
+
+static void s3c64xx_spi_dt_gpio_free(struct s3c64xx_spi_driver_data *sdd)
+{
+ unsigned int idx;
+ for (idx = 0; idx < 3; idx++)
+ gpio_free(sdd->gpios[idx]);
+}
+
+static struct __devinit s3c64xx_spi_info * s3c64xx_spi_parse_dt(
+ struct device *dev)
+{
+ struct s3c64xx_spi_info *sci;
+ u32 temp;
+
+ sci = devm_kzalloc(dev, sizeof(*sci), GFP_KERNEL);
+ if (!sci) {
+ dev_err(dev, "memory allocation for spi_info failed\n");
+ return ERR_PTR(-ENOMEM);
+ }
+
+ if (of_property_read_u32(dev->of_node, "samsung,spi-src-clk", &temp)) {
+ dev_warn(dev, "spi bus clock parent not specified, using "
+ "clock at index 0 as parent\n");
+ sci->src_clk_nr = 0;
+ } else {
+ sci->src_clk_nr = temp;
+ }
+
+ if (of_property_read_u32(dev->of_node, "num-cs", &temp)) {
+ dev_warn(dev, "number of chip select lines not specified, "
+ "assuming 1 chip select line\n");
+ sci->num_cs = 1;
+ } else {
+ sci->num_cs = temp;
+ }
+
+ return sci;
+}
+#else
+static struct s3c64xx_spi_info *s3c64xx_spi_parse_dt(struct device *dev)
+{
+ return dev->platform_data;
+}
+
+static int s3c64xx_spi_parse_dt_gpio(struct s3c64xx_spi_driver_data *sdd)
+{
+ return -EINVAL;
+}
+
+static void s3c64xx_spi_dt_gpio_free(struct s3c64xx_spi_driver_data *sdd)
+{
+}
+#endif
+
+static const struct of_device_id s3c64xx_spi_dt_match[];
+
static inline struct s3c64xx_spi_port_config *s3c64xx_spi_get_port_config(
struct platform_device *pdev)
{
+#ifdef CONFIG_OF
+ if (pdev->dev.of_node) {
+ const struct of_device_id *match;
+ match = of_match_node(s3c64xx_spi_dt_match, pdev->dev.of_node);
+ return (struct s3c64xx_spi_port_config *)match->data;
+ }
+#endif
return (struct s3c64xx_spi_port_config *)
platform_get_device_id(pdev)->driver_data;
}
static int __init s3c64xx_spi_probe(struct platform_device *pdev)
{
- struct resource *mem_res, *dmatx_res, *dmarx_res;
+ struct resource *mem_res;
struct s3c64xx_spi_driver_data *sdd;
- struct s3c64xx_spi_info *sci;
+ struct s3c64xx_spi_info *sci = pdev->dev.platform_data;
struct spi_master *master;
int ret, irq;
char clk_name[16];
- if (pdev->id < 0) {
- dev_err(&pdev->dev,
- "Invalid platform device id-%d\n", pdev->id);
- return -ENODEV;
+ if (!sci && pdev->dev.of_node) {
+ sci = s3c64xx_spi_parse_dt(&pdev->dev);
+ if (IS_ERR(sci))
+ return PTR_ERR(sci);
}
- if (pdev->dev.platform_data == NULL) {
+ if (!sci) {
dev_err(&pdev->dev, "platform_data missing!\n");
return -ENODEV;
}
- sci = pdev->dev.platform_data;
-
- /* Check for availability of necessary resource */
-
- dmatx_res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
- if (dmatx_res == NULL) {
- dev_err(&pdev->dev, "Unable to get SPI-Tx dma resource\n");
- return -ENXIO;
- }
-
- dmarx_res = platform_get_resource(pdev, IORESOURCE_DMA, 1);
- if (dmarx_res == NULL) {
- dev_err(&pdev->dev, "Unable to get SPI-Rx dma resource\n");
- return -ENXIO;
- }
-
mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (mem_res == NULL) {
dev_err(&pdev->dev, "Unable to get SPI MEM resource\n");
@@ -1036,18 +1208,34 @@ static int __init s3c64xx_spi_probe(struct platform_device *pdev)
sdd = spi_master_get_devdata(master);
sdd->port_conf = s3c64xx_spi_get_port_config(pdev);
+
sdd->master = master;
sdd->cntrlr_info = sci;
sdd->pdev = pdev;
sdd->sfr_start = mem_res->start;
- sdd->tx_dma.dmach = dmatx_res->start;
- sdd->tx_dma.direction = DMA_MEM_TO_DEV;
- sdd->rx_dma.dmach = dmarx_res->start;
- sdd->rx_dma.direction = DMA_DEV_TO_MEM;
- sdd->port_id = pdev->id;
+ if (pdev->dev.of_node) {
+ ret = of_alias_get_id(pdev->dev.of_node, "spi");
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to get alias id, "
+ "errno %d\n", ret);
+ goto err0;
+ }
+ sdd->port_id = ret;
+ } else {
+ sdd->port_id = pdev->id;
+ }
sdd->cur_bpw = 8;
+ ret = s3c64xx_spi_get_dmares(sdd, true);
+ if (ret)
+ goto err0;
+
+ ret = s3c64xx_spi_get_dmares(sdd, false);
+ if (ret)
+ goto err0;
+
+ master->dev.of_node = pdev->dev.of_node;
master->bus_num = sdd->port_id;
master->setup = s3c64xx_spi_setup;
master->prepare_transfer_hardware = s3c64xx_spi_prepare_transfer;
@@ -1072,7 +1260,10 @@ static int __init s3c64xx_spi_probe(struct platform_device *pdev)
goto err1;
}
- if (sci->cfg_gpio == NULL || sci->cfg_gpio()) {
+ if (!sci->cfg_gpio && pdev->dev.of_node) {
+ if (s3c64xx_spi_parse_dt_gpio(sdd))
+ return -EBUSY;
+ } else if (sci->cfg_gpio == NULL || sci->cfg_gpio()) {
dev_err(&pdev->dev, "Unable to config gpio\n");
ret = -EBUSY;
goto err2;
@@ -1153,6 +1344,8 @@ err5:
err4:
clk_put(sdd->clk);
err3:
+ if (!sdd->cntrlr_info->cfg_gpio && pdev->dev.of_node)
+ s3c64xx_spi_dt_gpio_free(sdd);
err2:
iounmap((void *) sdd->regs);
err1:
@@ -1184,6 +1377,9 @@ static int s3c64xx_spi_remove(struct platform_device *pdev)
clk_disable(sdd->clk);
clk_put(sdd->clk);
+ if (!sdd->cntrlr_info->cfg_gpio && pdev->dev.of_node)
+ s3c64xx_spi_dt_gpio_free(sdd);
+
iounmap((void *) sdd->regs);
mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -1208,6 +1404,9 @@ static int s3c64xx_spi_suspend(struct device *dev)
clk_disable(sdd->src_clk);
clk_disable(sdd->clk);
+ if (!sdd->cntrlr_info->cfg_gpio && dev->of_node)
+ s3c64xx_spi_dt_gpio_free(sdd);
+
sdd->cur_speed = 0; /* Output Clock is stopped */
return 0;
@@ -1219,7 +1418,10 @@ static int s3c64xx_spi_resume(struct device *dev)
struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
- sci->cfg_gpio();
+ if (!sci->cfg_gpio && dev->of_node)
+ s3c64xx_spi_parse_dt_gpio(sdd);
+ else
+ sci->cfg_gpio();
/* Enable the clock */
clk_enable(sdd->src_clk);
@@ -1327,11 +1529,22 @@ static struct platform_device_id s3c64xx_spi_driver_ids[] = {
{ },
};
+#ifdef CONFIG_OF
+static const struct of_device_id s3c64xx_spi_dt_match[] = {
+ { .compatible = "samsung,exynos4210-spi",
+ .data = (void *)&exynos4_spi_port_config,
+ },
+ { },
+};
+MODULE_DEVICE_TABLE(of, s3c64xx_spi_dt_match);
+#endif /* CONFIG_OF */
+
static struct platform_driver s3c64xx_spi_driver = {
.driver = {
.name = "s3c64xx-spi",
.owner = THIS_MODULE,
.pm = &s3c64xx_spi_pm,
+ .of_match_table = of_match_ptr(s3c64xx_spi_dt_match),
},
.remove = s3c64xx_spi_remove,
.id_table = s3c64xx_spi_driver_ids,
--
1.6.6.rc2
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