1 /* 2 * (C) Copyright 2016 3 * Vikas Manocha, <vikas.manocha@st.com> 4 * 5 * SPDX-License-Identifier: GPL-2.0+ 6 */ 7 8 #include <common.h> 9 #include <dm.h> 10 #include <asm/io.h> 11 #include <serial.h> 12 #include <dm/platform_data/serial_stm32x7.h> 13 #include "serial_stm32x7.h" 14 15 DECLARE_GLOBAL_DATA_PTR; 16 17 static int stm32_serial_setbrg(struct udevice *dev, int baudrate) 18 { 19 struct stm32x7_serial_platdata *plat = dev->platdata; 20 struct stm32_usart *const usart = plat->base; 21 writel(plat->clock/baudrate, &usart->brr); 22 23 return 0; 24 } 25 26 static int stm32_serial_getc(struct udevice *dev) 27 { 28 struct stm32x7_serial_platdata *plat = dev->platdata; 29 struct stm32_usart *const usart = plat->base; 30 31 if ((readl(&usart->sr) & USART_SR_FLAG_RXNE) == 0) 32 return -EAGAIN; 33 34 return readl(&usart->rd_dr); 35 } 36 37 static int stm32_serial_putc(struct udevice *dev, const char c) 38 { 39 struct stm32x7_serial_platdata *plat = dev->platdata; 40 struct stm32_usart *const usart = plat->base; 41 42 if ((readl(&usart->sr) & USART_SR_FLAG_TXE) == 0) 43 return -EAGAIN; 44 45 writel(c, &usart->tx_dr); 46 47 return 0; 48 } 49 50 static int stm32_serial_pending(struct udevice *dev, bool input) 51 { 52 struct stm32x7_serial_platdata *plat = dev->platdata; 53 struct stm32_usart *const usart = plat->base; 54 55 if (input) 56 return readl(&usart->sr) & USART_SR_FLAG_RXNE ? 1 : 0; 57 else 58 return readl(&usart->sr) & USART_SR_FLAG_TXE ? 0 : 1; 59 } 60 61 static int stm32_serial_probe(struct udevice *dev) 62 { 63 struct stm32x7_serial_platdata *plat = dev->platdata; 64 struct stm32_usart *const usart = plat->base; 65 setbits_le32(&usart->cr1, USART_CR1_RE | USART_CR1_TE | USART_CR1_UE); 66 67 return 0; 68 } 69 70 static const struct dm_serial_ops stm32_serial_ops = { 71 .putc = stm32_serial_putc, 72 .pending = stm32_serial_pending, 73 .getc = stm32_serial_getc, 74 .setbrg = stm32_serial_setbrg, 75 }; 76 77 U_BOOT_DRIVER(serial_stm32) = { 78 .name = "serial_stm32x7", 79 .id = UCLASS_SERIAL, 80 .ops = &stm32_serial_ops, 81 .probe = stm32_serial_probe, 82 .flags = DM_FLAG_PRE_RELOC, 83 }; 84