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path: root/drivers/gpio/gpio-ixp4xx.c
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Diffstat (limited to 'drivers/gpio/gpio-ixp4xx.c')
-rw-r--r--drivers/gpio/gpio-ixp4xx.c51
1 files changed, 50 insertions, 1 deletions
diff --git a/drivers/gpio/gpio-ixp4xx.c b/drivers/gpio/gpio-ixp4xx.c
index dde6cf3a57..c5a9fa6405 100644
--- a/drivers/gpio/gpio-ixp4xx.c
+++ b/drivers/gpio/gpio-ixp4xx.c
@@ -38,6 +38,18 @@
#define IXP4XX_GPIO_STYLE_MASK GENMASK(2, 0)
#define IXP4XX_GPIO_STYLE_SIZE 3
+/*
+ * Clock output control register defines.
+ */
+#define IXP4XX_GPCLK_CLK0DC_SHIFT 0
+#define IXP4XX_GPCLK_CLK0TC_SHIFT 4
+#define IXP4XX_GPCLK_CLK0_MASK GENMASK(7, 0)
+#define IXP4XX_GPCLK_MUX14 BIT(8)
+#define IXP4XX_GPCLK_CLK1DC_SHIFT 16
+#define IXP4XX_GPCLK_CLK1TC_SHIFT 20
+#define IXP4XX_GPCLK_CLK1_MASK GENMASK(23, 16)
+#define IXP4XX_GPCLK_MUX15 BIT(24)
+
/**
* struct ixp4xx_gpio - IXP4 GPIO state container
* @dev: containing device for this instance
@@ -202,6 +214,8 @@ static int ixp4xx_gpio_probe(struct platform_device *pdev)
struct ixp4xx_gpio *g;
struct gpio_irq_chip *girq;
struct device_node *irq_parent;
+ bool clk_14, clk_15;
+ u32 val;
int ret;
g = devm_kzalloc(dev, sizeof(*g), GFP_KERNEL);
@@ -226,12 +240,47 @@ static int ixp4xx_gpio_probe(struct platform_device *pdev)
g->fwnode = of_node_to_fwnode(np);
/*
+ * If either clock output is enabled explicitly in the device tree
+ * we take full control of the clock by masking off all bits for
+ * the clock control and selectively enabling them. Otherwise
+ * we leave the hardware default settings.
+ *
+ * Enable clock outputs with default timings of requested clock.
+ * If you need control over TC and DC, add these to the device
+ * tree bindings and use them here.
+ */
+ clk_14 = of_property_read_bool(np, "intel,ixp4xx-gpio14-clkout");
+ clk_15 = of_property_read_bool(np, "intel,ixp4xx-gpio15-clkout");
+
+ /*
* Make sure GPIO 14 and 15 are NOT used as clocks but GPIO on
* specific machines.
*/
if (of_machine_is_compatible("dlink,dsm-g600-a") ||
of_machine_is_compatible("iom,nas-100d"))
- __raw_writel(0x0, g->base + IXP4XX_REG_GPCLK);
+ val = 0;
+ else {
+ val = __raw_readl(g->base + IXP4XX_REG_GPCLK);
+
+ if (clk_14 || clk_15) {
+ val &= ~(IXP4XX_GPCLK_MUX14 | IXP4XX_GPCLK_MUX15);
+ val &= ~IXP4XX_GPCLK_CLK0_MASK;
+ val &= ~IXP4XX_GPCLK_CLK1_MASK;
+ if (clk_14) {
+ /* IXP4XX_GPCLK_CLK0DC implicit low */
+ val |= (1 << IXP4XX_GPCLK_CLK0TC_SHIFT);
+ val |= IXP4XX_GPCLK_MUX14;
+ }
+
+ if (clk_15) {
+ /* IXP4XX_GPCLK_CLK1DC implicit low */
+ val |= (1 << IXP4XX_GPCLK_CLK1TC_SHIFT);
+ val |= IXP4XX_GPCLK_MUX15;
+ }
+ }
+ }
+
+ __raw_writel(val, g->base + IXP4XX_REG_GPCLK);
/*
* This is a very special big-endian ARM issue: when the IXP4xx is