--- /dev/null
+/*
+ * Copyright (C) 2015-2016 Wills Wang <wills.wang@live.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <div64.h>
+#include <errno.h>
+#include <serial.h>
+#include <asm/io.h>
+#include <asm/addrspace.h>
+#include <asm/types.h>
+#include <dm/pinctrl.h>
+#include <mach/ar71xx_regs.h>
+
+#define AR933X_UART_DATA_REG 0x00
+#define AR933X_UART_CS_REG 0x04
+#define AR933X_UART_CLK_REG 0x08
+
+#define AR933X_UART_DATA_TX_RX_MASK 0xff
+#define AR933X_UART_DATA_RX_CSR BIT(8)
+#define AR933X_UART_DATA_TX_CSR BIT(9)
+#define AR933X_UART_CS_IF_MODE_S 2
+#define AR933X_UART_CS_IF_MODE_M 0x3
+#define AR933X_UART_CS_IF_MODE_DTE 1
+#define AR933X_UART_CS_IF_MODE_DCE 2
+#define AR933X_UART_CS_TX_RDY_ORIDE BIT(7)
+#define AR933X_UART_CS_RX_RDY_ORIDE BIT(8)
+#define AR933X_UART_CLK_STEP_M 0xffff
+#define AR933X_UART_CLK_SCALE_M 0xfff
+#define AR933X_UART_CLK_SCALE_S 16
+#define AR933X_UART_CLK_STEP_S 0
+
+struct ar933x_serial_priv {
+ void __iomem *regs;
+};
+
+/*
+ * baudrate = (clk / (scale + 1)) * (step * (1 / 2^17))
+ */
+static u32 ar933x_serial_get_baud(u32 clk, u32 scale, u32 step)
+{
+ u64 t;
+ u32 div;
+
+ div = (2 << 16) * (scale + 1);
+ t = clk;
+ t *= step;
+ t += (div / 2);
+ do_div(t, div);
+
+ return t;
+}
+
+static void ar933x_serial_get_scale_step(u32 clk, u32 baud,
+ u32 *scale, u32 *step)
+{
+ u32 tscale, baudrate;
+ long min_diff;
+
+ *scale = 0;
+ *step = 0;
+
+ min_diff = baud;
+ for (tscale = 0; tscale < AR933X_UART_CLK_SCALE_M; tscale++) {
+ u64 tstep;
+ int diff;
+
+ tstep = baud * (tscale + 1);
+ tstep *= (2 << 16);
+ do_div(tstep, clk);
+
+ if (tstep > AR933X_UART_CLK_STEP_M)
+ break;
+
+ baudrate = ar933x_serial_get_baud(clk, tscale, tstep);
+ diff = abs(baudrate - baud);
+ if (diff < min_diff) {
+ min_diff = diff;
+ *scale = tscale;
+ *step = tstep;
+ }
+ }
+}
+
+static int ar933x_serial_setbrg(struct udevice *dev, int baudrate)
+{
+ struct ar933x_serial_priv *priv = dev_get_priv(dev);
+ u32 val, scale, step;
+
+ val = get_serial_clock();
+ ar933x_serial_get_scale_step(val, baudrate, &scale, &step);
+
+ val = (scale & AR933X_UART_CLK_SCALE_M)
+ << AR933X_UART_CLK_SCALE_S;
+ val |= (step & AR933X_UART_CLK_STEP_M)
+ << AR933X_UART_CLK_STEP_S;
+ writel(val, priv->regs + AR933X_UART_CLK_REG);
+
+ return 0;
+}
+
+static int ar933x_serial_putc(struct udevice *dev, const char c)
+{
+ struct ar933x_serial_priv *priv = dev_get_priv(dev);
+ u32 data;
+
+ data = readl(priv->regs + AR933X_UART_DATA_REG);
+ if (!(data & AR933X_UART_DATA_TX_CSR))
+ return -EAGAIN;
+
+ data = (u32)c | AR933X_UART_DATA_TX_CSR;
+ writel(data, priv->regs + AR933X_UART_DATA_REG);
+
+ return 0;
+}
+
+static int ar933x_serial_getc(struct udevice *dev)
+{
+ struct ar933x_serial_priv *priv = dev_get_priv(dev);
+ u32 data;
+
+ data = readl(priv->regs + AR933X_UART_DATA_REG);
+ if (!(data & AR933X_UART_DATA_RX_CSR))
+ return -EAGAIN;
+
+ writel(AR933X_UART_DATA_RX_CSR, priv->regs + AR933X_UART_DATA_REG);
+ return data & AR933X_UART_DATA_TX_RX_MASK;
+}
+
+static int ar933x_serial_pending(struct udevice *dev, bool input)
+{
+ struct ar933x_serial_priv *priv = dev_get_priv(dev);
+ u32 data;
+
+ data = readl(priv->regs + AR933X_UART_DATA_REG);
+ if (input)
+ return (data & AR933X_UART_DATA_RX_CSR) ? 1 : 0;
+ else
+ return (data & AR933X_UART_DATA_TX_CSR) ? 0 : 1;
+}
+
+static int ar933x_serial_probe(struct udevice *dev)
+{
+ struct ar933x_serial_priv *priv = dev_get_priv(dev);
+ struct udevice *pinctrl;
+ fdt_addr_t addr;
+ u32 val;
+ int ret;
+
+ ret = uclass_get_device(UCLASS_PINCTRL, 0, &pinctrl);
+ if (ret)
+ return ret;
+ ret = pinctrl_get_periph_id(pinctrl, dev);
+ if (ret < 0)
+ return ret;
+ ret = pinctrl_request(pinctrl, ret, 0);
+ if (ret < 0)
+ return ret;
+
+ addr = dev_get_addr(dev);
+ if (addr == FDT_ADDR_T_NONE)
+ return -EINVAL;
+
+ priv->regs = map_physmem(addr,
+ AR933X_UART_SIZE,
+ MAP_NOCACHE);
+
+ /*
+ * UART controller configuration:
+ * - no DMA
+ * - no interrupt
+ * - DCE mode
+ * - no flow control
+ * - set RX ready oride
+ * - set TX ready oride
+ */
+ val = (AR933X_UART_CS_IF_MODE_DCE << AR933X_UART_CS_IF_MODE_S) |
+ AR933X_UART_CS_TX_RDY_ORIDE | AR933X_UART_CS_RX_RDY_ORIDE;
+ writel(val, priv->regs + AR933X_UART_CS_REG);
+ return 0;
+}
+
+static const struct dm_serial_ops ar933x_serial_ops = {
+ .putc = ar933x_serial_putc,
+ .pending = ar933x_serial_pending,
+ .getc = ar933x_serial_getc,
+ .setbrg = ar933x_serial_setbrg,
+};
+
+static const struct udevice_id ar933x_serial_ids[] = {
+ { .compatible = "qca,ar9330-uart" },
+ { }
+};
+
+U_BOOT_DRIVER(serial_ar933x) = {
+ .name = "serial_ar933x",
+ .id = UCLASS_SERIAL,
+ .of_match = ar933x_serial_ids,
+ .priv_auto_alloc_size = sizeof(struct ar933x_serial_priv),
+ .probe = ar933x_serial_probe,
+ .ops = &ar933x_serial_ops,
+ .flags = DM_FLAG_PRE_RELOC,
+};
+
+#ifdef CONFIG_DEBUG_UART_AR933X
+
+#include <debug_uart.h>
+
+static inline void _debug_uart_init(void)
+{
+ void __iomem *regs = (void *)CONFIG_DEBUG_UART_BASE;
+ u32 val, scale, step;
+
+ /*
+ * UART controller configuration:
+ * - no DMA
+ * - no interrupt
+ * - DCE mode
+ * - no flow control
+ * - set RX ready oride
+ * - set TX ready oride
+ */
+ val = (AR933X_UART_CS_IF_MODE_DCE << AR933X_UART_CS_IF_MODE_S) |
+ AR933X_UART_CS_TX_RDY_ORIDE | AR933X_UART_CS_RX_RDY_ORIDE;
+ writel(val, regs + AR933X_UART_CS_REG);
+
+ ar933x_serial_get_scale_step(CONFIG_DEBUG_UART_CLOCK,
+ CONFIG_BAUDRATE, &scale, &step);
+
+ val = (scale & AR933X_UART_CLK_SCALE_M)
+ << AR933X_UART_CLK_SCALE_S;
+ val |= (step & AR933X_UART_CLK_STEP_M)
+ << AR933X_UART_CLK_STEP_S;
+ writel(val, regs + AR933X_UART_CLK_REG);
+}
+
+static inline void _debug_uart_putc(int c)
+{
+ void __iomem *regs = (void *)CONFIG_DEBUG_UART_BASE;
+ u32 data;
+
+ do {
+ data = readl(regs + AR933X_UART_DATA_REG);
+ } while (!(data & AR933X_UART_DATA_TX_CSR));
+
+ data = (u32)c | AR933X_UART_DATA_TX_CSR;
+ writel(data, regs + AR933X_UART_DATA_REG);
+}
+
+DEBUG_UART_FUNCS
+
+#endif
projects / oweals / u-boot.git / commitdiff