3 * Vikas Manocha, <vikas.manocha@st.com>
5 * SPDX-License-Identifier: GPL-2.0+
13 #include <asm/arch/stm32.h>
14 #include "serial_stm32x7.h"
16 DECLARE_GLOBAL_DATA_PTR;
18 static int stm32_serial_setbrg(struct udevice *dev, int baudrate)
20 struct stm32x7_serial_platdata *plat = dev->platdata;
21 struct stm32_usart *const usart = plat->base;
22 u32 clock, int_div, mantissa, fraction, oversampling;
24 if (((u32)usart & STM32_BUS_MASK) == APB1_PERIPH_BASE)
25 clock = clock_get(CLOCK_APB1);
26 else if (((u32)usart & STM32_BUS_MASK) == APB2_PERIPH_BASE)
27 clock = clock_get(CLOCK_APB2);
31 int_div = DIV_ROUND_CLOSEST(clock, baudrate);
35 setbits_le32(&usart->cr1, USART_CR1_OVER8);
38 clrbits_le32(&usart->cr1, USART_CR1_OVER8);
41 mantissa = (int_div / oversampling) << USART_BRR_M_SHIFT;
42 fraction = int_div % oversampling;
44 writel(mantissa | fraction, &usart->brr);
49 static int stm32_serial_getc(struct udevice *dev)
51 struct stm32x7_serial_platdata *plat = dev->platdata;
52 struct stm32_usart *const usart = plat->base;
54 if ((readl(&usart->sr) & USART_SR_FLAG_RXNE) == 0)
57 return readl(&usart->rd_dr);
60 static int stm32_serial_putc(struct udevice *dev, const char c)
62 struct stm32x7_serial_platdata *plat = dev->platdata;
63 struct stm32_usart *const usart = plat->base;
65 if ((readl(&usart->sr) & USART_SR_FLAG_TXE) == 0)
68 writel(c, &usart->tx_dr);
73 static int stm32_serial_pending(struct udevice *dev, bool input)
75 struct stm32x7_serial_platdata *plat = dev->platdata;
76 struct stm32_usart *const usart = plat->base;
79 return readl(&usart->sr) & USART_SR_FLAG_RXNE ? 1 : 0;
81 return readl(&usart->sr) & USART_SR_FLAG_TXE ? 0 : 1;
84 static int stm32_serial_probe(struct udevice *dev)
86 struct stm32x7_serial_platdata *plat = dev->platdata;
87 struct stm32_usart *const usart = plat->base;
93 ret = clk_get_by_index(dev, 0, &clk);
97 ret = clk_enable(&clk);
99 dev_err(dev, "failed to enable clock\n");
104 /* Disable usart-> disable overrun-> enable usart */
105 clrbits_le32(&usart->cr1, USART_CR1_RE | USART_CR1_TE | USART_CR1_UE);
106 setbits_le32(&usart->cr3, USART_CR3_OVRDIS);
107 setbits_le32(&usart->cr1, USART_CR1_RE | USART_CR1_TE | USART_CR1_UE);
112 #if CONFIG_IS_ENABLED(OF_CONTROL)
113 static const struct udevice_id stm32_serial_id[] = {
114 {.compatible = "st,stm32f7-usart"},
115 {.compatible = "st,stm32f7-uart"},
119 static int stm32_serial_ofdata_to_platdata(struct udevice *dev)
121 struct stm32x7_serial_platdata *plat = dev_get_platdata(dev);
124 addr = devfdt_get_addr(dev);
125 if (addr == FDT_ADDR_T_NONE)
128 plat->base = (struct stm32_usart *)addr;
134 static const struct dm_serial_ops stm32_serial_ops = {
135 .putc = stm32_serial_putc,
136 .pending = stm32_serial_pending,
137 .getc = stm32_serial_getc,
138 .setbrg = stm32_serial_setbrg,
141 U_BOOT_DRIVER(serial_stm32) = {
142 .name = "serial_stm32x7",
144 .of_match = of_match_ptr(stm32_serial_id),
145 .ofdata_to_platdata = of_match_ptr(stm32_serial_ofdata_to_platdata),
146 .platdata_auto_alloc_size = sizeof(struct stm32x7_serial_platdata),
147 .ops = &stm32_serial_ops,
148 .probe = stm32_serial_probe,
149 .flags = DM_FLAG_PRE_RELOC,