[PATCH v1 4/9] serial: npcm: Add support for Nuvoton NPCM SoCs
Stanley Chu
stanley.chuys at gmail.com
Wed Dec 15 03:57:55 CET 2021
Add Nuvoton BMC NPCM7xx/NPCM8xx uart driver
Signed-off-by: Stanley Chu <yschu at nuvoton.com>
---
arch/arm/include/asm/arch-npcm8xx/uart.h | 82 ++++++++++++++
drivers/serial/Kconfig | 7 ++
drivers/serial/Makefile | 1 +
drivers/serial/serial_npcm.c | 137 +++++++++++++++++++++++
4 files changed, 227 insertions(+)
create mode 100644 arch/arm/include/asm/arch-npcm8xx/uart.h
create mode 100644 drivers/serial/serial_npcm.c
diff --git a/arch/arm/include/asm/arch-npcm8xx/uart.h b/arch/arm/include/asm/arch-npcm8xx/uart.h
new file mode 100644
index 0000000000..e3c86849f3
--- /dev/null
+++ b/arch/arm/include/asm/arch-npcm8xx/uart.h
@@ -0,0 +1,82 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+
+#ifndef _NPCM_UART_H_
+#define _NPCM_UART_H_
+
+struct npcm_uart {
+ union {
+ unsigned int rbr;
+ unsigned int thr;
+ unsigned int dll;
+ };
+ union {
+ unsigned int ier;
+ unsigned int dlm;
+ };
+ union {
+ unsigned int iir;
+ unsigned int fcr;
+ };
+ unsigned int lcr;
+ unsigned int mcr;
+ unsigned int lsr;
+ unsigned int msr;
+ unsigned int tor;
+};
+
+#define IER_DBGACK BIT(4)
+#define IER_MSIE BIT(3)
+#define IER_RLSE BIT(2)
+#define IER_THREIE BIT(1)
+#define IER_RDAIE BIT(0)
+
+#define IIR_FMES BIT(7)
+#define IIR_RFTLS BIT(5)
+#define IIR_DMS BIT(4)
+#define IIR_IID BIT(1)
+#define IIR_NIP BIT(0)
+
+#define FCR_RFITL_1B (0 << 4)
+#define FCR_RFITL_4B (4 << 4)
+#define FCR_RFITL_8B (8 << 4)
+#define FCR_RFITL_14B (12 << 4)
+#define FCR_DMS BIT(3)
+#define FCR_TFR BIT(2)
+#define FCR_RFR BIT(1)
+#define FCR_FME BIT(0)
+
+#define LCR_DLAB BIT(7)
+#define LCR_BCB BIT(6)
+#define LCR_SPE BIT(5)
+#define LCR_EPS BIT(4)
+#define LCR_PBE BIT(3)
+#define LCR_NSB BIT(2)
+#define LCR_WLS_8b 3
+#define LCR_WLS_7b 2
+#define LCR_WLS_6b 1
+#define LCR_WLS_5b 0
+
+#define MCR_LBME BIT(4)
+#define MCR_OUT2 BIT(3)
+#define MCR_RTS BIT(1)
+#define MCR_DTR BIT(0)
+
+#define LSR_ERR_RX BIT(7)
+#define LSR_TE BIT(6)
+#define LSR_THRE BIT(5)
+#define LSR_BII BIT(4)
+#define LSR_FEI BIT(3)
+#define LSR_PEI BIT(2)
+#define LSR_OEI BIT(1)
+#define LSR_RFDR BIT(0)
+
+#define MSR_DCD BIT(7)
+#define MSR_RI BIT(6)
+#define MSR_DSR BIT(5)
+#define MSR_CTS BIT(4)
+#define MSR_DDCD BIT(3)
+#define MSR_DRI BIT(2)
+#define MSR_DDSR BIT(1)
+#define MSR_DCTS BIT(0)
+
+#endif
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index 6c8fdda9a0..3982bc9426 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -975,4 +975,11 @@ config SYS_SDMR
depends on MPC8XX_CONS
default 0
+config NPCM_SERIAL
+ bool "Nuvoton NPCM UART driver"
+ depends on DM_SERIAL
+ help
+ Select this to enable UART support for Nuvoton BMCs
+ (NPCM7xx and NPCM8xx)
+
endif
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index 8168af640f..1b86acf5cf 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -75,6 +75,7 @@ obj-$(CONFIG_MTK_SERIAL) += serial_mtk.o
obj-$(CONFIG_MT7620_SERIAL) += serial_mt7620.o
obj-$(CONFIG_SIFIVE_SERIAL) += serial_sifive.o
obj-$(CONFIG_XEN_SERIAL) += serial_xen.o
+obj-$(CONFIG_NPCM_SERIAL) += serial_npcm.o
ifndef CONFIG_SPL_BUILD
obj-$(CONFIG_USB_TTY) += usbtty.o
diff --git a/drivers/serial/serial_npcm.c b/drivers/serial/serial_npcm.c
new file mode 100644
index 0000000000..330c544e5a
--- /dev/null
+++ b/drivers/serial/serial_npcm.c
@@ -0,0 +1,137 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2021 Nuvoton Technology Corp.
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <serial.h>
+#include <clk.h>
+#include <asm/arch/uart.h>
+
+struct npcm_serial_plat {
+ struct npcm_uart *reg;
+ u32 uart_clk;
+};
+
+static int npcm_serial_init(struct npcm_uart *uart)
+{
+ u8 val;
+
+ /* Disable all UART interrupt */
+ writeb(0, &uart->ier);
+
+ /* Set port for 8 bit, 1 stop, no parity */
+ val = LCR_WLS_8b;
+ writeb(val, &uart->lcr);
+
+ /* Set the RX FIFO trigger level, reset RX, TX FIFO */
+ val = FCR_FME | FCR_RFR | FCR_TFR | FCR_RFITL_4B;
+ writeb(val, &uart->fcr);
+
+ return 0;
+}
+
+static int npcm_serial_pending(struct udevice *dev, bool input)
+{
+ struct npcm_serial_plat *plat = dev_get_plat(dev);
+ struct npcm_uart *const uart = plat->reg;
+
+ if (input)
+ return (readb(&uart->lsr) & LSR_RFDR);
+ else
+ return !(readb(&uart->lsr) & LSR_THRE);
+
+ return 0;
+}
+
+static int npcm_serial_putc(struct udevice *dev, const char ch)
+{
+ struct npcm_serial_plat *plat = dev_get_plat(dev);
+ struct npcm_uart *const uart = plat->reg;
+
+ while (!(readl(&uart->lsr) & LSR_THRE))
+ ;
+
+ writeb(ch, &uart->thr);
+
+ return 0;
+}
+
+static int npcm_serial_getc(struct udevice *dev)
+{
+ struct npcm_serial_plat *plat = dev_get_plat(dev);
+ struct npcm_uart *const uart = plat->reg;
+
+ while (!(readl(&uart->lsr) & LSR_RFDR))
+ ;
+
+ return (int)(readb(&uart->rbr) & 0xff);
+}
+
+static int npcm_serial_setbrg(struct udevice *dev, int baudrate)
+{
+ struct npcm_serial_plat *plat = dev_get_plat(dev);
+ struct npcm_uart *const uart = plat->reg;
+ int ret = 0;
+ u32 divisor;
+
+ /* BaudOut = UART Clock / (16 * [Divisor + 2]) */
+ divisor = DIV_ROUND_CLOSEST(plat->uart_clk, 16 * baudrate + 2) - 2;
+
+ writeb(readb(&uart->lcr) | LCR_DLAB, &uart->lcr);
+ writeb(divisor & 0xff, &uart->dll);
+ writeb(divisor >> 8, &uart->dlm);
+ writeb(readb(&uart->lcr) & (~LCR_DLAB), &uart->lcr);
+
+ return ret;
+}
+
+static int npcm_serial_probe(struct udevice *dev)
+{
+ struct npcm_serial_plat *plat = dev_get_plat(dev);
+ struct npcm_uart *const uart = plat->reg;
+ struct clk clk;
+ u32 freq;
+ int ret;
+
+ plat->reg = (struct npcm_uart *)dev_read_addr_ptr(dev);
+ freq = dev_read_u32_default(dev, "clock-frequency", 0);
+
+ ret = clk_get_by_index(dev, 0, &clk);
+ if (ret < 0) {
+ printf("Cannot get clk for uart\n");
+ return ret;
+ }
+ ret = clk_set_rate(&clk, freq);
+ if (ret < 0)
+ return ret;
+ plat->uart_clk = ret;
+
+ npcm_serial_init(uart);
+
+ return 0;
+}
+
+static const struct dm_serial_ops npcm_serial_ops = {
+ .getc = npcm_serial_getc,
+ .setbrg = npcm_serial_setbrg,
+ .putc = npcm_serial_putc,
+ .pending = npcm_serial_pending,
+};
+
+static const struct udevice_id npcm_serial_ids[] = {
+ { .compatible = "nuvoton,npcm750-uart" },
+ { .compatible = "nuvoton,npcm845-uart" },
+ { }
+};
+
+U_BOOT_DRIVER(serial_npcm) = {
+ .name = "serial_npcm",
+ .id = UCLASS_SERIAL,
+ .of_match = npcm_serial_ids,
+ .plat_auto = sizeof(struct npcm_serial_plat),
+ .probe = npcm_serial_probe,
+ .ops = &npcm_serial_ops,
+ .flags = DM_FLAG_PRE_RELOC,
+};
--
2.17.1
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