diff options
Diffstat (limited to 'drivers/serial/serial_mtk.c')
| -rw-r--r-- | drivers/serial/serial_mtk.c | 80 |
1 files changed, 47 insertions, 33 deletions
diff --git a/drivers/serial/serial_mtk.c b/drivers/serial/serial_mtk.c index 22251c5f4c..03b9e86bfc 100644 --- a/drivers/serial/serial_mtk.c +++ b/drivers/serial/serial_mtk.c @@ -10,6 +10,7 @@ #include <common.h> #include <div64.h> #include <dm.h> +#include <dm/device_compat.h> #include <errno.h> #include <log.h> #include <serial.h> @@ -70,27 +71,37 @@ struct mtk_serial_regs { #define BAUD_ALLOW_MAX(baud) ((baud) + (baud) * 3 / 100) #define BAUD_ALLOW_MIX(baud) ((baud) - (baud) * 3 / 100) +/* struct mtk_serial_priv - Structure holding all information used by the + * driver + * @regs: Register base of the serial port + * @clk: The baud clock device + * @fixed_clk_rate: Fallback fixed baud clock rate if baud clock + * device is not specified + * @force_highspeed: Force using high-speed mode + */ struct mtk_serial_priv { struct mtk_serial_regs __iomem *regs; - u32 clock; + struct clk clk; + u32 fixed_clk_rate; bool force_highspeed; }; -static void _mtk_serial_setbrg(struct mtk_serial_priv *priv, int baud) +static void _mtk_serial_setbrg(struct mtk_serial_priv *priv, int baud, + uint clk_rate) { u32 quot, realbaud, samplecount = 1; /* Special case for low baud clock */ - if (baud <= 115200 && priv->clock <= 12000000) { + if (baud <= 115200 && clk_rate == 12000000) { writel(3, &priv->regs->highspeed); - quot = DIV_ROUND_CLOSEST(priv->clock, 256 * baud); + quot = DIV_ROUND_CLOSEST(clk_rate, 256 * baud); if (quot == 0) quot = 1; - samplecount = DIV_ROUND_CLOSEST(priv->clock, quot * baud); + samplecount = DIV_ROUND_CLOSEST(clk_rate, quot * baud); - realbaud = priv->clock / samplecount / quot; + realbaud = clk_rate / samplecount / quot; if (realbaud > BAUD_ALLOW_MAX(baud) || realbaud < BAUD_ALLOW_MIX(baud)) { pr_info("baud %d can't be handled\n", baud); @@ -104,7 +115,7 @@ static void _mtk_serial_setbrg(struct mtk_serial_priv *priv, int baud) if (baud <= 115200) { writel(0, &priv->regs->highspeed); - quot = DIV_ROUND_CLOSEST(priv->clock, 16 * baud); + quot = DIV_ROUND_CLOSEST(clk_rate, 16 * baud); } else if (baud <= 576000) { writel(2, &priv->regs->highspeed); @@ -112,13 +123,13 @@ static void _mtk_serial_setbrg(struct mtk_serial_priv *priv, int baud) if ((baud == 500000) || (baud == 576000)) baud = 460800; - quot = DIV_ROUND_UP(priv->clock, 4 * baud); + quot = DIV_ROUND_UP(clk_rate, 4 * baud); } else { use_hs3: writel(3, &priv->regs->highspeed); - quot = DIV_ROUND_UP(priv->clock, 256 * baud); - samplecount = DIV_ROUND_CLOSEST(priv->clock, quot * baud); + quot = DIV_ROUND_UP(clk_rate, 256 * baud); + samplecount = DIV_ROUND_CLOSEST(clk_rate, quot * baud); } set_baud: @@ -167,8 +178,13 @@ static int _mtk_serial_pending(struct mtk_serial_priv *priv, bool input) static int mtk_serial_setbrg(struct udevice *dev, int baudrate) { struct mtk_serial_priv *priv = dev_get_priv(dev); + u32 clk_rate; + + clk_rate = clk_get_rate(&priv->clk); + if (IS_ERR_VALUE(clk_rate) || clk_rate == 0) + clk_rate = priv->fixed_clk_rate; - _mtk_serial_setbrg(priv, baudrate); + _mtk_serial_setbrg(priv, baudrate, clk_rate); return 0; } @@ -211,7 +227,6 @@ static int mtk_serial_of_to_plat(struct udevice *dev) { struct mtk_serial_priv *priv = dev_get_priv(dev); fdt_addr_t addr; - struct clk clk; int err; addr = dev_read_addr(dev); @@ -220,22 +235,19 @@ static int mtk_serial_of_to_plat(struct udevice *dev) priv->regs = map_physmem(addr, 0, MAP_NOCACHE); - err = clk_get_by_index(dev, 0, &clk); - if (!err) { - err = clk_get_rate(&clk); - if (!IS_ERR_VALUE(err)) - priv->clock = err; - } else if (err != -ENOENT && err != -ENODEV && err != -ENOSYS) { - debug("mtk_serial: failed to get clock\n"); - return err; - } - - if (!priv->clock) - priv->clock = dev_read_u32_default(dev, "clock-frequency", 0); - - if (!priv->clock) { - debug("mtk_serial: clock not defined\n"); - return -EINVAL; + err = clk_get_by_index(dev, 0, &priv->clk); + if (err) { + err = dev_read_u32(dev, "clock-frequency", &priv->fixed_clk_rate); + if (err) { + dev_err(dev, "baud clock not defined\n"); + return -EINVAL; + } + } else { + err = clk_get_rate(&priv->clk); + if (IS_ERR_VALUE(err)) { + dev_err(dev, "invalid baud clock\n"); + return -EINVAL; + } } priv->force_highspeed = dev_read_bool(dev, "mediatek,force-highspeed"); @@ -273,7 +285,7 @@ DECLARE_GLOBAL_DATA_PTR; #define DECLARE_HSUART_PRIV(port) \ static struct mtk_serial_priv mtk_hsuart##port = { \ .regs = (struct mtk_serial_regs *)CONFIG_SYS_NS16550_COM##port, \ - .clock = CONFIG_SYS_NS16550_CLK \ + .fixed_clk_rate = CONFIG_SYS_NS16550_CLK \ }; #define DECLARE_HSUART_FUNCTIONS(port) \ @@ -282,12 +294,14 @@ DECLARE_GLOBAL_DATA_PTR; writel(0, &mtk_hsuart##port.regs->ier); \ writel(UART_MCRVAL, &mtk_hsuart##port.regs->mcr); \ writel(UART_FCRVAL, &mtk_hsuart##port.regs->fcr); \ - _mtk_serial_setbrg(&mtk_hsuart##port, gd->baudrate); \ + _mtk_serial_setbrg(&mtk_hsuart##port, gd->baudrate, \ + mtk_hsuart##port.fixed_clk_rate); \ return 0 ; \ } \ static void mtk_serial##port##_setbrg(void) \ { \ - _mtk_serial_setbrg(&mtk_hsuart##port, gd->baudrate); \ + _mtk_serial_setbrg(&mtk_hsuart##port, gd->baudrate, \ + mtk_hsuart##port.fixed_clk_rate); \ } \ static int mtk_serial##port##_getc(void) \ { \ @@ -427,13 +441,13 @@ static inline void _debug_uart_init(void) struct mtk_serial_priv priv; priv.regs = (void *) CONFIG_VAL(DEBUG_UART_BASE); - priv.clock = CONFIG_DEBUG_UART_CLOCK; + priv.fixed_clk_rate = CONFIG_DEBUG_UART_CLOCK; writel(0, &priv.regs->ier); writel(UART_MCRVAL, &priv.regs->mcr); writel(UART_FCRVAL, &priv.regs->fcr); - _mtk_serial_setbrg(&priv, CONFIG_BAUDRATE); + _mtk_serial_setbrg(&priv, CONFIG_BAUDRATE, priv.fixed_clk_rate); } static inline void _debug_uart_putc(int ch) |