Add driver model support so that ns16550 can support operation both with and without driver model.
The driver needs a clock frequency so cannot stand alone unfortunately. The clock frequency must be provided by a separate driver.
Signed-off-by: Simon Glass sjg@chromium.org ---
Changes in v4: - Remove clock frequency setup for ns16550 driver
Changes in v3: - Add new patch to support driver model in ns16550
Changes in v2: None
doc/device-tree-bindings/serial/ns16550.txt | 10 ++ drivers/serial/Makefile | 2 +- drivers/serial/ns16550.c | 156 +++++++++++++++++++++++++++- include/ns16550.h | 51 +++++++++ 4 files changed, 216 insertions(+), 3 deletions(-) create mode 100644 doc/device-tree-bindings/serial/ns16550.txt
diff --git a/doc/device-tree-bindings/serial/ns16550.txt b/doc/device-tree-bindings/serial/ns16550.txt new file mode 100644 index 0000000..ef0b9ae --- /dev/null +++ b/doc/device-tree-bindings/serial/ns16550.txt @@ -0,0 +1,10 @@ +NS16550 UART + +This UART driver supports many chip variants and is used in mamy SoCs. + +Required properties: +- compatible: "ns16550" or "nvidia,tegra20-uart" +- reg: start address and size of registers +- reg-shift: shift value indicating register size: 0=byte, 1=16bit,2=32bit etc. +- clock-frequency: input clock frequency for the UART (used to calculate the + baud rate divisor) diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile index 4720e1d..5ae6416 100644 --- a/drivers/serial/Makefile +++ b/drivers/serial/Makefile @@ -9,6 +9,7 @@ ifdef CONFIG_DM_SERIAL obj-y += serial-uclass.o else obj-y += serial.o +obj-$(CONFIG_SYS_NS16550_SERIAL) += serial_ns16550.o endif
obj-$(CONFIG_ALTERA_UART) += altera_uart.o @@ -20,7 +21,6 @@ obj-$(CONFIG_MCFUART) += mcfuart.o obj-$(CONFIG_OPENCORES_YANU) += opencores_yanu.o obj-$(CONFIG_SYS_NS16550) += ns16550.o obj-$(CONFIG_S5P) += serial_s5p.o -obj-$(CONFIG_SYS_NS16550_SERIAL) += serial_ns16550.o obj-$(CONFIG_IMX_SERIAL) += serial_imx.o obj-$(CONFIG_KS8695_SERIAL) += serial_ks8695.o obj-$(CONFIG_MAX3100_SERIAL) += serial_max3100.o diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c index 185e7a8..b3e297e 100644 --- a/drivers/serial/ns16550.c +++ b/drivers/serial/ns16550.c @@ -5,17 +5,25 @@ */
#include <common.h> +#include <dm.h> +#include <errno.h> +#include <fdtdec.h> #include <ns16550.h> +#include <serial.h> #include <watchdog.h> #include <linux/types.h> #include <asm/io.h>
+DECLARE_GLOBAL_DATA_PTR; + #define UART_LCRVAL UART_LCR_8N1 /* 8 data, 1 stop, no parity */ #define UART_MCRVAL (UART_MCR_DTR | \ UART_MCR_RTS) /* RTS/DTR */ #define UART_FCRVAL (UART_FCR_FIFO_EN | \ UART_FCR_RXSR | \ UART_FCR_TXSR) /* Clear & enable FIFOs */ + +#ifndef CONFIG_DM_SERIAL #ifdef CONFIG_SYS_NS16550_PORT_MAPPED #define serial_out(x, y) outb(x, (ulong)y) #define serial_in(y) inb((ulong)y) @@ -29,6 +37,7 @@ #define serial_out(x, y) writeb(x, y) #define serial_in(y) readb(y) #endif +#endif /* !CONFIG_DM_SERIAL */
#if defined(CONFIG_SOC_KEYSTONE) #define UART_REG_VAL_PWREMU_MGMT_UART_DISABLE 0 @@ -45,6 +54,58 @@ #define CONFIG_SYS_NS16550_IER 0x00 #endif /* CONFIG_SYS_NS16550_IER */
+#ifdef CONFIG_DM_SERIAL +static void ns16550_writeb(NS16550_t port, int offset, int value) +{ + struct ns16550_platdata *plat = port->plat; + unsigned char *addr; + + offset *= 1 << plat->reg_shift; + addr = plat->base + offset; + /* + * As far as we know it doesn't make sense to support selection of + * these options at run-time, so use the existing CONFIG options. + */ +#ifdef CONFIG_SYS_NS16550_PORT_MAPPED + outb(value, addr); +#elif defined(CONFIG_SYS_NS16550_MEM32) && !defined(CONFIG_SYS_BIG_ENDIAN) + out_le32(addr, value); +#elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_BIG_ENDIAN) + out_be32(addr, value); +#elif defined(CONFIG_SYS_BIG_ENDIAN) + writeb(value, addr + (1 << plat->reg_shift) - 1); +#else + writeb(value, addr); +#endif +} + +static int ns16550_readb(NS16550_t port, int offset) +{ + struct ns16550_platdata *plat = port->plat; + unsigned char *addr; + + offset *= 1 << plat->reg_shift; + addr = plat->base + offset; +#ifdef CONFIG_SYS_NS16550_PORT_MAPPED + return inb(addr); +#elif defined(CONFIG_SYS_NS16550_MEM32) && !defined(CONFIG_SYS_BIG_ENDIAN) + return in_le32(addr); +#elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_BIG_ENDIAN) + return in_be32(addr); +#elif defined(CONFIG_SYS_BIG_ENDIAN) + return readb(addr + (1 << plat->reg_shift) - 1); +#else + return readb(addr); +#endif +} + +/* We can clean these up once everything is moved to driver model */ +#define serial_out(value, addr) \ + ns16550_writeb(com_port, addr - (unsigned char *)com_port, value) +#define serial_in(addr) \ + ns16550_readb(com_port, addr - (unsigned char *)com_port) +#endif + int ns16550_calc_divisor(NS16550_t port, int clock, int baudrate) { const unsigned int mode_x_div = 16; @@ -79,7 +140,8 @@ void NS16550_init(NS16550_t com_port, int baud_divisor) */ if ((serial_in(&com_port->lsr) & (UART_LSR_TEMT | UART_LSR_THRE)) == UART_LSR_THRE) { - NS16550_setbrg(com_port, baud_divisor); + if (baud_divisor != -1) + NS16550_setbrg(com_port, baud_divisor); serial_out(0, &com_port->mdr1); } #endif @@ -95,7 +157,8 @@ void NS16550_init(NS16550_t com_port, int baud_divisor) NS16550_setbrg(com_port, 0); serial_out(UART_MCRVAL, &com_port->mcr); serial_out(UART_FCRVAL, &com_port->fcr); - NS16550_setbrg(com_port, baud_divisor); + if (baud_divisor != -1) + NS16550_setbrg(com_port, baud_divisor); #if (defined(CONFIG_OMAP) && !defined(CONFIG_OMAP3_ZOOM2)) || \ defined(CONFIG_AM33XX) || defined(CONFIG_SOC_DA8XX) || \ defined(CONFIG_TI81XX) || defined(CONFIG_AM43XX) @@ -154,3 +217,92 @@ int NS16550_tstc(NS16550_t com_port) }
#endif /* CONFIG_NS16550_MIN_FUNCTIONS */ + +#ifdef CONFIG_DM_SERIAL +static int ns16550_serial_putc(struct udevice *dev, const char ch) +{ + struct NS16550 *const com_port = dev_get_priv(dev); + + if (!(serial_in(&com_port->lsr) & UART_LSR_THRE)) + return -EAGAIN; + serial_out(ch, &com_port->thr); + + /* + * Call watchdog_reset() upon newline. This is done here in putc + * since the environment code uses a single puts() to print the complete + * environment upon "printenv". So we can't put this watchdog call + * in puts(). + */ + if (ch == '\n') + WATCHDOG_RESET(); + + return 0; +} + +static int ns16550_serial_pending(struct udevice *dev, bool input) +{ + struct NS16550 *const com_port = dev_get_priv(dev); + + if (input) + return serial_in(&com_port->lsr) & UART_LSR_DR ? 1 : 0; + else + return serial_in(&com_port->lsr) & UART_LSR_THRE ? 0 : 1; +} + +static int ns16550_serial_getc(struct udevice *dev) +{ + struct NS16550 *const com_port = dev_get_priv(dev); + + if (!serial_in(&com_port->lsr) & UART_LSR_DR) + return -EAGAIN; + + return serial_in(&com_port->rbr); +} + +static int ns16550_serial_setbrg(struct udevice *dev, int baudrate) +{ + struct NS16550 *const com_port = dev_get_priv(dev); + struct ns16550_platdata *plat = com_port->plat; + int clock_divisor; + + clock_divisor = ns16550_calc_divisor(com_port, plat->clock, baudrate); + + NS16550_setbrg(com_port, clock_divisor); + + return 0; +} + +int ns16550_serial_probe(struct udevice *dev) +{ + struct NS16550 *const com_port = dev_get_priv(dev); + + NS16550_init(com_port, -1); + + return 0; +} + +int ns16550_serial_ofdata_to_platdata(struct udevice *dev) +{ + struct NS16550 *const com_port = dev_get_priv(dev); + struct ns16550_platdata *plat = dev->platdata; + fdt_addr_t addr; + + addr = fdtdec_get_addr(gd->fdt_blob, dev->of_offset, "reg"); + if (addr == FDT_ADDR_T_NONE) + return -EINVAL; + + plat->base = (unsigned char *)addr; + plat->reg_shift = fdtdec_get_int(gd->fdt_blob, dev->of_offset, + "reg-shift", 1); + com_port->plat = plat; + + return 0; +} + +const struct dm_serial_ops ns16550_serial_ops = { + .putc = ns16550_serial_putc, + .pending = ns16550_serial_pending, + .getc = ns16550_serial_getc, + .setbrg = ns16550_serial_setbrg, +}; +#endif /* CONFIG_DM_SERIAL */ diff --git a/include/ns16550.h b/include/ns16550.h index b106f8a..9212c68 100644 --- a/include/ns16550.h +++ b/include/ns16550.h @@ -23,6 +23,14 @@
#include <linux/types.h>
+#ifdef CONFIG_DM_SERIAL +/* + * For driver model we always use one byte per register, and sort out the + * differences in the driver + */ +#define CONFIG_SYS_NS16550_REG_SIZE (-1) +#endif + #if !defined(CONFIG_SYS_NS16550_REG_SIZE) || (CONFIG_SYS_NS16550_REG_SIZE == 0) #error "Please define NS16550 registers size." #elif defined(CONFIG_SYS_NS16550_MEM32) @@ -37,6 +45,19 @@ unsigned char postpad_##x[-CONFIG_SYS_NS16550_REG_SIZE - 1]; #endif
+/** + * struct ns16550_platdata - information about a NS16550 port + * + * @base: Base register address + * @reg_shift: Shift size of registers (0=byte, 1=16bit, 2=32bit...) + * @clock: UART base clock speed in Hz + */ +struct ns16550_platdata { + unsigned char *base; + int reg_shift; + int clock; +}; + struct NS16550 { UART_REG(rbr); /* 0 */ UART_REG(ier); /* 1 */ @@ -67,6 +88,9 @@ struct NS16550 { UART_REG(reg12); /* 12*/ UART_REG(osc_12m_sel); /* 13*/ #endif +#ifdef CONFIG_DM_SERIAL + struct ns16550_platdata *plat; +#endif };
#define thr rbr @@ -190,3 +214,30 @@ void NS16550_reinit(NS16550_t com_port, int baud_divisor); * @return baud rate divisor that should be used */ int ns16550_calc_divisor(NS16550_t port, int clock, int baudrate); + +/** + * ns16550_serial_ofdata_to_platdata() - convert DT to platform data + * + * Decode a device tree node for an ns16550 device. This includes the + * register base address and register shift properties. The caller must set + * up the clock frequency. + * + * @dev: dev to decode platform data for + * @return: 0 if OK, -EINVAL on error + */ +int ns16550_serial_ofdata_to_platdata(struct udevice *dev); + +/** + * ns16550_serial_probe() - probe a serial port + * + * This sets up the serial port ready for use, except for the baud rate + * @return 0, or -ve on error + */ +int ns16550_serial_probe(struct udevice *dev); + +/** + * struct ns16550_serial_ops - ns16550 serial operations + * + * These should be used by the client driver for the driver's 'ops' member + */ +extern const struct dm_serial_ops ns16550_serial_ops;