Messages in this thread Patch in this message | | | From | Alan Tull <> | Subject | [PATCH] gpio: gpio-dwapb: add optional reset | Date | Tue, 10 Oct 2017 16:26:17 -0500 |
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Some platforms require reset to be released to allow register access.
Signed-off-by: Alan Tull <atull@kernel.org> --- drivers/gpio/gpio-dwapb.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)
diff --git a/drivers/gpio/gpio-dwapb.c b/drivers/gpio/gpio-dwapb.c index 5cdb7bc..f7ac625 100644 --- a/drivers/gpio/gpio-dwapb.c +++ b/drivers/gpio/gpio-dwapb.c @@ -25,6 +25,7 @@ #include <linux/of_irq.h> #include <linux/platform_device.h> #include <linux/property.h> +#include <linux/reset.h> #include <linux/spinlock.h> #include <linux/platform_data/gpio-dwapb.h> #include <linux/slab.h> @@ -98,6 +99,7 @@ struct dwapb_gpio { unsigned int nr_ports; struct irq_domain *domain; unsigned int flags; + struct reset_control *rst; }; static inline u32 gpio_reg_v2_convert(unsigned int offset) @@ -612,6 +614,7 @@ static int dwapb_gpio_probe(struct platform_device *pdev) int err; struct device *dev = &pdev->dev; struct dwapb_platform_data *pdata = dev_get_platdata(dev); + struct reset_control *rst; if (!pdata) { pdata = dwapb_gpio_get_pdata(dev); @@ -629,6 +632,15 @@ static int dwapb_gpio_probe(struct platform_device *pdev) gpio->dev = &pdev->dev; gpio->nr_ports = pdata->nports; + rst = devm_reset_control_get_optional_exclusive(dev, NULL); + if (IS_ERR(rst)) { + if (PTR_ERR(rst) == -EPROBE_DEFER) + return PTR_ERR(rst); + } else { + reset_control_deassert(rst); + gpio->rst = rst; + } + gpio->ports = devm_kcalloc(&pdev->dev, gpio->nr_ports, sizeof(*gpio->ports), GFP_KERNEL); if (!gpio->ports) @@ -680,6 +692,8 @@ static int dwapb_gpio_remove(struct platform_device *pdev) dwapb_gpio_unregister(gpio); dwapb_irq_teardown(gpio); + if (gpio->rst) + reset_control_assert(gpio->rst); return 0; } -- 2.7.4
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