Use of_get_named_gpio_flags to retrieve the "nshutdown" gpio connected to the BT_EN pin of the device when retrieving platform data from device tree.
This allows the polarity to be specified using GPIO_ACTIVE_HIGH/LOW in device tree. Signed-off-by: Eric Nelson <[email protected]> --- V2 changes comments to use "assert" and "de-assert" to refer to the state of the nshutdown gpio instead of low/high/0/1. drivers/misc/ti-st/st_kim.c | 34 +++++++++++++++++++++------------- include/linux/ti_wilink_st.h | 6 +++--- 2 files changed, 24 insertions(+), 16 deletions(-) diff --git a/drivers/misc/ti-st/st_kim.c b/drivers/misc/ti-st/st_kim.c index aaa17b0..54d5f50 100644 --- a/drivers/misc/ti-st/st_kim.c +++ b/drivers/misc/ti-st/st_kim.c @@ -32,6 +32,7 @@ #include <linux/sched.h> #include <linux/sysfs.h> #include <linux/tty.h> +#include <linux/of_gpio.h> #include <linux/skbuff.h> #include <linux/ti_wilink_st.h> @@ -481,10 +482,13 @@ long st_kim_start(void *kim_data) if (pdata->chip_enable) pdata->chip_enable(kim_gdata); - /* Configure BT nShutdown to HIGH state */ - gpio_set_value(kim_gdata->nshutdown, GPIO_LOW); + /* + * De-assert nShutdown (enable bluetooth), + * but force a transition + */ + gpio_set_value(kim_gdata->nshutdown, kim_gdata->shutdown_val); mdelay(5); /* FIXME: a proper toggle */ - gpio_set_value(kim_gdata->nshutdown, GPIO_HIGH); + gpio_set_value(kim_gdata->nshutdown, !kim_gdata->shutdown_val); mdelay(100); /* re-initialize the completion */ reinit_completion(&kim_gdata->ldisc_installed); @@ -527,7 +531,7 @@ long st_kim_start(void *kim_data) * (b) upon failure to either install ldisc or download firmware. * The function is responsible to (a) notify UIM about un-installation, * (b) flush UART if the ldisc was installed. - * (c) reset BT_EN - pull down nshutdown at the end. + * (c) reset BT_EN - assert nshutdown at the end. * (d) invoke platform's chip disabling routine. */ long st_kim_stop(void *kim_data) @@ -565,12 +569,12 @@ long st_kim_stop(void *kim_data) err = -ETIMEDOUT; } - /* By default configure BT nShutdown to LOW state */ - gpio_set_value(kim_gdata->nshutdown, GPIO_LOW); + /* Assert nShutdown (chip disabled), but force transitions */ + gpio_set_value(kim_gdata->nshutdown, kim_gdata->shutdown_val); mdelay(1); - gpio_set_value(kim_gdata->nshutdown, GPIO_HIGH); + gpio_set_value(kim_gdata->nshutdown, !kim_gdata->shutdown_val); mdelay(1); - gpio_set_value(kim_gdata->nshutdown, GPIO_LOW); + gpio_set_value(kim_gdata->nshutdown, kim_gdata->shutdown_val); /* platform specific disable */ if (pdata->chip_disable) @@ -749,6 +753,7 @@ static struct ti_st_plat_data *get_platform_data(struct device *dev) { struct device_node *np = dev->of_node; const u32 *dt_property; + enum of_gpio_flags flags; int len; dt_pdata = kzalloc(sizeof(*dt_pdata), GFP_KERNEL); @@ -759,8 +764,9 @@ static struct ti_st_plat_data *get_platform_data(struct device *dev) dt_property = of_get_property(np, "dev_name", &len); if (dt_property) memcpy(&dt_pdata->dev_name, dt_property, len); - of_property_read_u32(np, "nshutdown_gpio", - &dt_pdata->nshutdown_gpio); + dt_pdata->nshutdown_gpio = of_get_named_gpio_flags + (np, "nshutdown_gpio", 0, &flags); + dt_pdata->shutdown_val = !(flags & OF_GPIO_ACTIVE_LOW); of_property_read_u32(np, "flow_cntrl", &dt_pdata->flow_cntrl); of_property_read_u32(np, "baud_rate", &dt_pdata->baud_rate); @@ -808,16 +814,18 @@ static int kim_probe(struct platform_device *pdev) /* refer to itself */ kim_gdata->core_data->kim_data = kim_gdata; - /* Claim the chip enable nShutdown gpio from the system */ + /* Claim the nShutdown GPIO */ kim_gdata->nshutdown = pdata->nshutdown_gpio; + kim_gdata->shutdown_val = pdata->shutdown_val; err = gpio_request(kim_gdata->nshutdown, "kim"); if (unlikely(err)) { pr_err(" gpio %d request failed ", kim_gdata->nshutdown); return err; } - /* Configure nShutdown GPIO as output=0 */ - err = gpio_direction_output(kim_gdata->nshutdown, GPIO_LOW); + /* Configure nShutdown GPIO as output and assert */ + err = gpio_direction_output(kim_gdata->nshutdown, + kim_gdata->shutdown_val); if (unlikely(err)) { pr_err(" unable to configure gpio %d", kim_gdata->nshutdown); return err; diff --git a/include/linux/ti_wilink_st.h b/include/linux/ti_wilink_st.h index c78dcfe..7154194 100644 --- a/include/linux/ti_wilink_st.h +++ b/include/linux/ti_wilink_st.h @@ -212,9 +212,6 @@ void gps_chrdrv_stub_init(void); #define MAKEWORD(a, b) ((unsigned short)(((unsigned char)(a)) \ | ((unsigned short)((unsigned char)(b))) << 8)) -#define GPIO_HIGH 1 -#define GPIO_LOW 0 - /* the Power-On-Reset logic, requires to attempt * to download firmware onto chip more than once * since the self-test for chip takes a while @@ -263,6 +260,7 @@ struct kim_data_s { char resp_buffer[30]; const struct firmware *fw_entry; unsigned nshutdown; + unsigned shutdown_val; unsigned long rx_state; unsigned long rx_count; struct sk_buff *rx_skb; @@ -418,6 +416,7 @@ struct gps_event_hdr { * struct ti_st_plat_data - platform data shared between ST driver and * platform specific board file which adds the ST device. * @nshutdown_gpio: Host's GPIO line to which chip's BT_EN is connected. + * @shutdown_val: shutdown state (0/1) of gpio * @dev_name: The UART/TTY name to which chip is interfaced. (eg: /dev/ttyS1) * @flow_cntrl: Should always be 1, since UART's CTS/RTS is used for PM * purposes. @@ -438,6 +437,7 @@ struct gps_event_hdr { */ struct ti_st_plat_data { u32 nshutdown_gpio; + int shutdown_val; unsigned char dev_name[UART_DEV_NAME_LEN]; /* uart name */ u32 flow_cntrl; /* flow control flag */ u32 baud_rate; -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
