1 // SPDX-License-Identifier: GPL-2.0+
3 * Copyright (C) 2016, STMicroelectronics - All Rights Reserved
4 * Author(s): Vikas Manocha, <vikas.manocha@st.com> for STMicroelectronics.
13 #include <asm/arch/stm32.h>
14 #include "serial_stm32.h"
16 static void _stm32_serial_setbrg(fdt_addr_t base,
17 struct stm32_uart_info *uart_info,
21 bool stm32f4 = uart_info->stm32f4;
22 u32 int_div, mantissa, fraction, oversampling;
24 int_div = DIV_ROUND_CLOSEST(clock_rate, baudrate);
28 setbits_le32(base + CR1_OFFSET(stm32f4), USART_CR1_OVER8);
31 clrbits_le32(base + CR1_OFFSET(stm32f4), USART_CR1_OVER8);
34 mantissa = (int_div / oversampling) << USART_BRR_M_SHIFT;
35 fraction = int_div % oversampling;
37 writel(mantissa | fraction, base + BRR_OFFSET(stm32f4));
40 static int stm32_serial_setbrg(struct udevice *dev, int baudrate)
42 struct stm32x7_serial_platdata *plat = dev_get_platdata(dev);
44 _stm32_serial_setbrg(plat->base, plat->uart_info,
45 plat->clock_rate, baudrate);
50 static int stm32_serial_setconfig(struct udevice *dev, uint serial_config)
52 struct stm32x7_serial_platdata *plat = dev_get_platdata(dev);
53 bool stm32f4 = plat->uart_info->stm32f4;
54 u8 uart_enable_bit = plat->uart_info->uart_enable_bit;
55 u32 cr1 = plat->base + CR1_OFFSET(stm32f4);
57 uint parity = SERIAL_GET_PARITY(serial_config);
58 uint bits = SERIAL_GET_BITS(serial_config);
59 uint stop = SERIAL_GET_STOP(serial_config);
62 * only parity config is implemented, check if other serial settings
63 * are the default one.
64 * (STM32F4 serial IP didn't support parity setting)
66 if (bits != SERIAL_8_BITS || stop != SERIAL_ONE_STOP || stm32f4)
67 return -ENOTSUPP; /* not supported in driver*/
69 clrbits_le32(cr1, USART_CR1_RE | USART_CR1_TE | BIT(uart_enable_bit));
70 /* update usart configuration (uart need to be disable)
71 * PCE: parity check enable
72 * PS : '0' : Even / '1' : Odd
73 * M[1:0] = '00' : 8 Data bits
74 * M[1:0] = '01' : 9 Data bits with parity
82 config = USART_CR1_PCE | USART_CR1_PS | USART_CR1_M0;
85 config = USART_CR1_PCE | USART_CR1_M0;
90 USART_CR1_PCE | USART_CR1_PS | USART_CR1_M1 |
93 setbits_le32(cr1, USART_CR1_RE | USART_CR1_TE | BIT(uart_enable_bit));
98 static int stm32_serial_getc(struct udevice *dev)
100 struct stm32x7_serial_platdata *plat = dev_get_platdata(dev);
101 bool stm32f4 = plat->uart_info->stm32f4;
102 fdt_addr_t base = plat->base;
103 u32 isr = readl(base + ISR_OFFSET(stm32f4));
105 if ((isr & USART_ISR_RXNE) == 0)
108 if (isr & (USART_ISR_PE | USART_ISR_ORE)) {
110 setbits_le32(base + ICR_OFFSET,
111 USART_ICR_PCECF | USART_ICR_ORECF);
113 readl(base + RDR_OFFSET(stm32f4));
117 return readl(base + RDR_OFFSET(stm32f4));
120 static int _stm32_serial_putc(fdt_addr_t base,
121 struct stm32_uart_info *uart_info,
124 bool stm32f4 = uart_info->stm32f4;
126 if ((readl(base + ISR_OFFSET(stm32f4)) & USART_ISR_TXE) == 0)
129 writel(c, base + TDR_OFFSET(stm32f4));
134 static int stm32_serial_putc(struct udevice *dev, const char c)
136 struct stm32x7_serial_platdata *plat = dev_get_platdata(dev);
138 return _stm32_serial_putc(plat->base, plat->uart_info, c);
141 static int stm32_serial_pending(struct udevice *dev, bool input)
143 struct stm32x7_serial_platdata *plat = dev_get_platdata(dev);
144 bool stm32f4 = plat->uart_info->stm32f4;
145 fdt_addr_t base = plat->base;
148 return readl(base + ISR_OFFSET(stm32f4)) &
149 USART_ISR_RXNE ? 1 : 0;
151 return readl(base + ISR_OFFSET(stm32f4)) &
152 USART_ISR_TXE ? 0 : 1;
155 static void _stm32_serial_init(fdt_addr_t base,
156 struct stm32_uart_info *uart_info)
158 bool stm32f4 = uart_info->stm32f4;
159 u8 uart_enable_bit = uart_info->uart_enable_bit;
161 /* Disable uart-> enable fifo -> enable uart */
162 clrbits_le32(base + CR1_OFFSET(stm32f4), USART_CR1_RE | USART_CR1_TE |
163 BIT(uart_enable_bit));
164 if (uart_info->has_fifo)
165 setbits_le32(base + CR1_OFFSET(stm32f4), USART_CR1_FIFOEN);
166 setbits_le32(base + CR1_OFFSET(stm32f4), USART_CR1_RE | USART_CR1_TE |
167 BIT(uart_enable_bit));
170 static int stm32_serial_probe(struct udevice *dev)
172 struct stm32x7_serial_platdata *plat = dev_get_platdata(dev);
176 plat->uart_info = (struct stm32_uart_info *)dev_get_driver_data(dev);
178 ret = clk_get_by_index(dev, 0, &clk);
182 ret = clk_enable(&clk);
184 dev_err(dev, "failed to enable clock\n");
188 plat->clock_rate = clk_get_rate(&clk);
189 if (plat->clock_rate < 0) {
191 return plat->clock_rate;
194 _stm32_serial_init(plat->base, plat->uart_info);
199 static const struct udevice_id stm32_serial_id[] = {
200 { .compatible = "st,stm32-uart", .data = (ulong)&stm32f4_info},
201 { .compatible = "st,stm32f7-uart", .data = (ulong)&stm32f7_info},
202 { .compatible = "st,stm32h7-uart", .data = (ulong)&stm32h7_info},
206 static int stm32_serial_ofdata_to_platdata(struct udevice *dev)
208 struct stm32x7_serial_platdata *plat = dev_get_platdata(dev);
210 plat->base = devfdt_get_addr(dev);
211 if (plat->base == FDT_ADDR_T_NONE)
217 static const struct dm_serial_ops stm32_serial_ops = {
218 .putc = stm32_serial_putc,
219 .pending = stm32_serial_pending,
220 .getc = stm32_serial_getc,
221 .setbrg = stm32_serial_setbrg,
222 .setconfig = stm32_serial_setconfig
225 U_BOOT_DRIVER(serial_stm32) = {
226 .name = "serial_stm32",
228 .of_match = of_match_ptr(stm32_serial_id),
229 .ofdata_to_platdata = of_match_ptr(stm32_serial_ofdata_to_platdata),
230 .platdata_auto_alloc_size = sizeof(struct stm32x7_serial_platdata),
231 .ops = &stm32_serial_ops,
232 .probe = stm32_serial_probe,
233 .flags = DM_FLAG_PRE_RELOC,
236 #ifdef CONFIG_DEBUG_UART_STM32
237 #include <debug_uart.h>
238 static inline struct stm32_uart_info *_debug_uart_info(void)
240 struct stm32_uart_info *uart_info;
242 #if defined(CONFIG_STM32F4)
243 uart_info = &stm32f4_info;
244 #elif defined(CONFIG_STM32F7)
245 uart_info = &stm32f7_info;
247 uart_info = &stm32h7_info;
252 static inline void _debug_uart_init(void)
254 fdt_addr_t base = CONFIG_DEBUG_UART_BASE;
255 struct stm32_uart_info *uart_info = _debug_uart_info();
257 _stm32_serial_init(base, uart_info);
258 _stm32_serial_setbrg(base, uart_info,
259 CONFIG_DEBUG_UART_CLOCK,
261 printf("DEBUG done\n");
264 static inline void _debug_uart_putc(int c)
266 fdt_addr_t base = CONFIG_DEBUG_UART_BASE;
267 struct stm32_uart_info *uart_info = _debug_uart_info();
269 while (_stm32_serial_putc(base, uart_info, c) == -EAGAIN)