diff options
Diffstat (limited to 'drivers/tty/serial/8250/8250_aspeed_vuart.c')
| -rw-r--r-- | drivers/tty/serial/8250/8250_aspeed_vuart.c | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/drivers/tty/serial/8250/8250_aspeed_vuart.c b/drivers/tty/serial/8250/8250_aspeed_vuart.c index 0438d9a905ce..6e67fd89445a 100644 --- a/drivers/tty/serial/8250/8250_aspeed_vuart.c +++ b/drivers/tty/serial/8250/8250_aspeed_vuart.c @@ -14,6 +14,8 @@ #include <linux/of_address.h> #include <linux/of_irq.h> #include <linux/of_platform.h> +#include <linux/regmap.h> +#include <linux/mfd/syscon.h> #include <linux/tty.h> #include <linux/tty_flip.h> #include <linux/clk.h> @@ -22,6 +24,7 @@ #define ASPEED_VUART_GCRA 0x20 #define ASPEED_VUART_GCRA_VUART_EN BIT(0) +#define ASPEED_VUART_GCRA_HOST_SIRQ_POLARITY BIT(1) #define ASPEED_VUART_GCRA_DISABLE_HOST_TX_DISCARD BIT(5) #define ASPEED_VUART_GCRB 0x24 #define ASPEED_VUART_GCRB_HOST_SIRQ_MASK GENMASK(7, 4) @@ -131,8 +134,53 @@ static ssize_t sirq_store(struct device *dev, struct device_attribute *attr, static DEVICE_ATTR_RW(sirq); +static ssize_t sirq_polarity_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct aspeed_vuart *vuart = dev_get_drvdata(dev); + u8 reg; + + reg = readb(vuart->regs + ASPEED_VUART_GCRA); + reg &= ASPEED_VUART_GCRA_HOST_SIRQ_POLARITY; + + return snprintf(buf, PAGE_SIZE - 1, "%u\n", reg ? 1 : 0); +} + +static void aspeed_vuart_set_sirq_polarity(struct aspeed_vuart *vuart, + bool polarity) +{ + u8 reg = readb(vuart->regs + ASPEED_VUART_GCRA); + + if (polarity) + reg |= ASPEED_VUART_GCRA_HOST_SIRQ_POLARITY; + else + reg &= ~ASPEED_VUART_GCRA_HOST_SIRQ_POLARITY; + + writeb(reg, vuart->regs + ASPEED_VUART_GCRA); +} + +static ssize_t sirq_polarity_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct aspeed_vuart *vuart = dev_get_drvdata(dev); + unsigned long val; + int err; + + err = kstrtoul(buf, 0, &val); + if (err) + return err; + + aspeed_vuart_set_sirq_polarity(vuart, val != 0); + + return count; +} + +static DEVICE_ATTR_RW(sirq_polarity); + static struct attribute *aspeed_vuart_attrs[] = { &dev_attr_sirq.attr, + &dev_attr_sirq_polarity.attr, &dev_attr_lpc_address.attr, NULL, }; @@ -302,8 +350,30 @@ static int aspeed_vuart_handle_irq(struct uart_port *port) return 1; } +static void aspeed_vuart_auto_configure_sirq_polarity( + struct aspeed_vuart *vuart, struct device_node *syscon_np, + u32 reg_offset, u32 reg_mask) +{ + struct regmap *regmap; + u32 value; + + regmap = syscon_node_to_regmap(syscon_np); + if (IS_ERR(regmap)) { + dev_warn(vuart->dev, + "could not get regmap for aspeed,sirq-polarity-sense\n"); + return; + } + if (regmap_read(regmap, reg_offset, &value)) { + dev_warn(vuart->dev, "could not read hw strap table\n"); + return; + } + + aspeed_vuart_set_sirq_polarity(vuart, (value & reg_mask) == 0); +} + static int aspeed_vuart_probe(struct platform_device *pdev) { + struct of_phandle_args sirq_polarity_sense_args; struct uart_8250_port port; struct aspeed_vuart *vuart; struct device_node *np; @@ -402,6 +472,20 @@ static int aspeed_vuart_probe(struct platform_device *pdev) vuart->line = rc; + rc = of_parse_phandle_with_fixed_args( + np, "aspeed,sirq-polarity-sense", 2, 0, + &sirq_polarity_sense_args); + if (rc < 0) { + dev_dbg(&pdev->dev, + "aspeed,sirq-polarity-sense property not found\n"); + } else { + aspeed_vuart_auto_configure_sirq_polarity( + vuart, sirq_polarity_sense_args.np, + sirq_polarity_sense_args.args[0], + BIT(sirq_polarity_sense_args.args[1])); + of_node_put(sirq_polarity_sense_args.np); + } + aspeed_vuart_set_enabled(vuart, true); aspeed_vuart_set_host_tx_discard(vuart, true); platform_set_drvdata(pdev, vuart); |