From 3b44af4f9f4d9aab7d369b06e7c53db274927582 Mon Sep 17 00:00:00 2001 From: Zev Weiss Date: Sun, 11 Apr 2021 22:47:10 -0500 Subject: [PATCH] serial: 8250_aspeed_vuart: refactor sirq and lpc address setting code This splits dedicated aspeed_vuart_set_{sirq,lpc_address}() functions out of the sysfs store functions in preparation for adding DT properties that will be poking the same registers. While we're at it, these functions now provide some basic bounds-checking on their arguments. Reviewed-by: Andrew Jeffery Signed-off-by: Zev Weiss Link: https://lore.kernel.org/r/20210412034712.16778-3-zev@bewilderbeest.net Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_aspeed_vuart.c | 51 ++++++++++++++------- 1 file changed, 35 insertions(+), 16 deletions(-) diff --git a/drivers/tty/serial/8250/8250_aspeed_vuart.c b/drivers/tty/serial/8250/8250_aspeed_vuart.c index c33e02cbde93..8433f8dbb186 100644 --- a/drivers/tty/serial/8250/8250_aspeed_vuart.c +++ b/drivers/tty/serial/8250/8250_aspeed_vuart.c @@ -72,22 +72,31 @@ static ssize_t lpc_address_show(struct device *dev, return snprintf(buf, PAGE_SIZE - 1, "0x%x\n", addr); } +static int aspeed_vuart_set_lpc_address(struct aspeed_vuart *vuart, u32 addr) +{ + if (addr > U16_MAX) + return -EINVAL; + + writeb(addr >> 8, vuart->regs + ASPEED_VUART_ADDRH); + writeb(addr >> 0, vuart->regs + ASPEED_VUART_ADDRL); + + return 0; +} + static ssize_t lpc_address_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; + u32 val; int err; - err = kstrtoul(buf, 0, &val); + err = kstrtou32(buf, 0, &val); if (err) return err; - writeb(val >> 8, vuart->regs + ASPEED_VUART_ADDRH); - writeb(val >> 0, vuart->regs + ASPEED_VUART_ADDRL); - - return count; + err = aspeed_vuart_set_lpc_address(vuart, val); + return err ? : count; } static DEVICE_ATTR_RW(lpc_address); @@ -105,27 +114,37 @@ static ssize_t sirq_show(struct device *dev, return snprintf(buf, PAGE_SIZE - 1, "%u\n", reg); } +static int aspeed_vuart_set_sirq(struct aspeed_vuart *vuart, u32 sirq) +{ + u8 reg; + + if (sirq > (ASPEED_VUART_GCRB_HOST_SIRQ_MASK >> ASPEED_VUART_GCRB_HOST_SIRQ_SHIFT)) + return -EINVAL; + + sirq <<= ASPEED_VUART_GCRB_HOST_SIRQ_SHIFT; + sirq &= ASPEED_VUART_GCRB_HOST_SIRQ_MASK; + + reg = readb(vuart->regs + ASPEED_VUART_GCRB); + reg &= ~ASPEED_VUART_GCRB_HOST_SIRQ_MASK; + reg |= sirq; + writeb(reg, vuart->regs + ASPEED_VUART_GCRB); + + return 0; +} + static ssize_t sirq_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; - u8 reg; err = kstrtoul(buf, 0, &val); if (err) return err; - val <<= ASPEED_VUART_GCRB_HOST_SIRQ_SHIFT; - val &= ASPEED_VUART_GCRB_HOST_SIRQ_MASK; - - reg = readb(vuart->regs + ASPEED_VUART_GCRB); - reg &= ~ASPEED_VUART_GCRB_HOST_SIRQ_MASK; - reg |= val; - writeb(reg, vuart->regs + ASPEED_VUART_GCRB); - - return count; + err = aspeed_vuart_set_sirq(vuart, val); + return err ? : count; } static DEVICE_ATTR_RW(sirq);