1 /* 2 * Copyright (C) 2011-2015 Vladimir Zapolskiy <vz@mleia.com> 3 * 4 * SPDX-License-Identifier: GPL-2.0+ 5 */ 6 7 #include <common.h> 8 #include <dm.h> 9 #include <serial.h> 10 #include <dm/platform_data/lpc32xx_hsuart.h> 11 12 #include <asm/arch/uart.h> 13 #include <linux/compiler.h> 14 15 struct lpc32xx_hsuart_priv { 16 struct hsuart_regs *hsuart; 17 }; 18 19 static int lpc32xx_serial_setbrg(struct udevice *dev, int baudrate) 20 { 21 struct lpc32xx_hsuart_priv *priv = dev_get_priv(dev); 22 struct hsuart_regs *hsuart = priv->hsuart; 23 u32 div; 24 25 /* UART rate = PERIPH_CLK / ((HSU_RATE + 1) x 14) */ 26 div = (get_serial_clock() / 14 + baudrate / 2) / baudrate - 1; 27 if (div > 255) 28 div = 255; 29 30 writel(div, &hsuart->rate); 31 32 return 0; 33 } 34 35 static int lpc32xx_serial_getc(struct udevice *dev) 36 { 37 struct lpc32xx_hsuart_priv *priv = dev_get_priv(dev); 38 struct hsuart_regs *hsuart = priv->hsuart; 39 40 if (!(readl(&hsuart->level) & HSUART_LEVEL_RX)) 41 return -EAGAIN; 42 43 return readl(&hsuart->rx) & HSUART_RX_DATA; 44 } 45 46 static int lpc32xx_serial_putc(struct udevice *dev, const char c) 47 { 48 struct lpc32xx_hsuart_priv *priv = dev_get_priv(dev); 49 struct hsuart_regs *hsuart = priv->hsuart; 50 51 /* Wait for empty FIFO */ 52 if (readl(&hsuart->level) & HSUART_LEVEL_TX) 53 return -EAGAIN; 54 55 writel(c, &hsuart->tx); 56 57 return 0; 58 } 59 60 static int lpc32xx_serial_pending(struct udevice *dev, bool input) 61 { 62 struct lpc32xx_hsuart_priv *priv = dev_get_priv(dev); 63 struct hsuart_regs *hsuart = priv->hsuart; 64 65 if (input) { 66 if (readl(&hsuart->level) & HSUART_LEVEL_RX) 67 return 1; 68 } else { 69 if (readl(&hsuart->level) & HSUART_LEVEL_TX) 70 return 1; 71 } 72 73 return 0; 74 } 75 76 static int lpc32xx_serial_init(struct hsuart_regs *hsuart) 77 { 78 /* Disable hardware RTS and CTS flow control, set up RX and TX FIFO */ 79 writel(HSUART_CTRL_TMO_16 | HSUART_CTRL_HSU_OFFSET(20) | 80 HSUART_CTRL_HSU_RX_TRIG_32 | HSUART_CTRL_HSU_TX_TRIG_0, 81 &hsuart->ctrl); 82 83 return 0; 84 } 85 86 static int lpc32xx_hsuart_probe(struct udevice *dev) 87 { 88 struct lpc32xx_hsuart_platdata *platdata = dev_get_platdata(dev); 89 struct lpc32xx_hsuart_priv *priv = dev_get_priv(dev); 90 91 priv->hsuart = (struct hsuart_regs *)platdata->base; 92 93 lpc32xx_serial_init(priv->hsuart); 94 95 return 0; 96 } 97 98 static const struct dm_serial_ops lpc32xx_hsuart_ops = { 99 .setbrg = lpc32xx_serial_setbrg, 100 .getc = lpc32xx_serial_getc, 101 .putc = lpc32xx_serial_putc, 102 .pending = lpc32xx_serial_pending, 103 }; 104 105 U_BOOT_DRIVER(lpc32xx_hsuart) = { 106 .name = "lpc32xx_hsuart", 107 .id = UCLASS_SERIAL, 108 .probe = lpc32xx_hsuart_probe, 109 .ops = &lpc32xx_hsuart_ops, 110 .priv_auto_alloc_size = sizeof(struct lpc32xx_hsuart_priv), 111 .flags = DM_FLAG_PRE_RELOC, 112 }; 113