diff options
Diffstat (limited to 'drivers/gpio/gpio-ixp4xx.c')
| -rw-r--r-- | drivers/gpio/gpio-ixp4xx.c | 51 |
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 |