xref: /openbmc/linux/drivers/tty/serial/stm32-usart.h (revision 7f28bcea)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copyright (C) Maxime Coquelin 2015
4  * Copyright (C) STMicroelectronics SA 2017
5  * Authors:  Maxime Coquelin <mcoquelin.stm32@gmail.com>
6  *	     Gerald Baeza <gerald_baeza@yahoo.fr>
7  */
8 
9 #define DRIVER_NAME "stm32-usart"
10 
11 struct stm32_usart_offsets {
12 	u8 cr1;
13 	u8 cr2;
14 	u8 cr3;
15 	u8 brr;
16 	u8 gtpr;
17 	u8 rtor;
18 	u8 rqr;
19 	u8 isr;
20 	u8 icr;
21 	u8 rdr;
22 	u8 tdr;
23 };
24 
25 struct stm32_usart_config {
26 	u8 uart_enable_bit; /* USART_CR1_UE */
27 	bool has_7bits_data;
28 	bool has_swap;
29 	bool has_wakeup;
30 	bool has_fifo;
31 	int fifosize;
32 };
33 
34 struct stm32_usart_info {
35 	struct stm32_usart_offsets ofs;
36 	struct stm32_usart_config cfg;
37 };
38 
39 #define UNDEF_REG 0xff
40 
41 /* USART_SR (F4) / USART_ISR (F7) */
42 #define USART_SR_PE		BIT(0)
43 #define USART_SR_FE		BIT(1)
44 #define USART_SR_NE		BIT(2)		/* F7 (NF for F4) */
45 #define USART_SR_ORE		BIT(3)
46 #define USART_SR_IDLE		BIT(4)
47 #define USART_SR_RXNE		BIT(5)
48 #define USART_SR_TC		BIT(6)
49 #define USART_SR_TXE		BIT(7)
50 #define USART_SR_CTSIF		BIT(9)
51 #define USART_SR_CTS		BIT(10)		/* F7 */
52 #define USART_SR_RTOF		BIT(11)		/* F7 */
53 #define USART_SR_EOBF		BIT(12)		/* F7 */
54 #define USART_SR_ABRE		BIT(14)		/* F7 */
55 #define USART_SR_ABRF		BIT(15)		/* F7 */
56 #define USART_SR_BUSY		BIT(16)		/* F7 */
57 #define USART_SR_CMF		BIT(17)		/* F7 */
58 #define USART_SR_SBKF		BIT(18)		/* F7 */
59 #define USART_SR_WUF		BIT(20)		/* H7 */
60 #define USART_SR_TEACK		BIT(21)		/* F7 */
61 #define USART_SR_ERR_MASK	(USART_SR_ORE | USART_SR_NE | USART_SR_FE |\
62 				 USART_SR_PE)
63 /* Dummy bits */
64 #define USART_SR_DUMMY_RX	BIT(16)
65 
66 /* USART_DR */
67 #define USART_DR_MASK		GENMASK(8, 0)
68 
69 /* USART_BRR */
70 #define USART_BRR_DIV_F_MASK	GENMASK(3, 0)
71 #define USART_BRR_DIV_M_MASK	GENMASK(15, 4)
72 #define USART_BRR_DIV_M_SHIFT	4
73 #define USART_BRR_04_R_SHIFT	1
74 
75 /* USART_CR1 */
76 #define USART_CR1_SBK		BIT(0)
77 #define USART_CR1_RWU		BIT(1)		/* F4 */
78 #define USART_CR1_UESM		BIT(1)		/* H7 */
79 #define USART_CR1_RE		BIT(2)
80 #define USART_CR1_TE		BIT(3)
81 #define USART_CR1_IDLEIE	BIT(4)
82 #define USART_CR1_RXNEIE	BIT(5)
83 #define USART_CR1_TCIE		BIT(6)
84 #define USART_CR1_TXEIE		BIT(7)
85 #define USART_CR1_PEIE		BIT(8)
86 #define USART_CR1_PS		BIT(9)
87 #define USART_CR1_PCE		BIT(10)
88 #define USART_CR1_WAKE		BIT(11)
89 #define USART_CR1_M0		BIT(12)		/* F7 (CR1_M for F4) */
90 #define USART_CR1_MME		BIT(13)		/* F7 */
91 #define USART_CR1_CMIE		BIT(14)		/* F7 */
92 #define USART_CR1_OVER8		BIT(15)
93 #define USART_CR1_DEDT_MASK	GENMASK(20, 16)	/* F7 */
94 #define USART_CR1_DEAT_MASK	GENMASK(25, 21)	/* F7 */
95 #define USART_CR1_RTOIE		BIT(26)		/* F7 */
96 #define USART_CR1_EOBIE		BIT(27)		/* F7 */
97 #define USART_CR1_M1		BIT(28)		/* F7 */
98 #define USART_CR1_IE_MASK	(GENMASK(8, 4) | BIT(14) | BIT(26) | BIT(27))
99 #define USART_CR1_FIFOEN	BIT(29)		/* H7 */
100 #define USART_CR1_DEAT_SHIFT 21
101 #define USART_CR1_DEDT_SHIFT 16
102 
103 /* USART_CR2 */
104 #define USART_CR2_ADD_MASK	GENMASK(3, 0)	/* F4 */
105 #define USART_CR2_ADDM7		BIT(4)		/* F7 */
106 #define USART_CR2_LBCL		BIT(8)
107 #define USART_CR2_CPHA		BIT(9)
108 #define USART_CR2_CPOL		BIT(10)
109 #define USART_CR2_CLKEN		BIT(11)
110 #define USART_CR2_STOP_2B	BIT(13)
111 #define USART_CR2_STOP_MASK	GENMASK(13, 12)
112 #define USART_CR2_LINEN		BIT(14)
113 #define USART_CR2_SWAP		BIT(15)		/* F7 */
114 #define USART_CR2_RXINV		BIT(16)		/* F7 */
115 #define USART_CR2_TXINV		BIT(17)		/* F7 */
116 #define USART_CR2_DATAINV	BIT(18)		/* F7 */
117 #define USART_CR2_MSBFIRST	BIT(19)		/* F7 */
118 #define USART_CR2_ABREN		BIT(20)		/* F7 */
119 #define USART_CR2_ABRMOD_MASK	GENMASK(22, 21)	/* F7 */
120 #define USART_CR2_RTOEN		BIT(23)		/* F7 */
121 #define USART_CR2_ADD_F7_MASK	GENMASK(31, 24)	/* F7 */
122 
123 /* USART_CR3 */
124 #define USART_CR3_EIE		BIT(0)
125 #define USART_CR3_IREN		BIT(1)
126 #define USART_CR3_IRLP		BIT(2)
127 #define USART_CR3_HDSEL		BIT(3)
128 #define USART_CR3_NACK		BIT(4)
129 #define USART_CR3_SCEN		BIT(5)
130 #define USART_CR3_DMAR		BIT(6)
131 #define USART_CR3_DMAT		BIT(7)
132 #define USART_CR3_RTSE		BIT(8)
133 #define USART_CR3_CTSE		BIT(9)
134 #define USART_CR3_CTSIE		BIT(10)
135 #define USART_CR3_ONEBIT	BIT(11)
136 #define USART_CR3_OVRDIS	BIT(12)		/* F7 */
137 #define USART_CR3_DDRE		BIT(13)		/* F7 */
138 #define USART_CR3_DEM		BIT(14)		/* F7 */
139 #define USART_CR3_DEP		BIT(15)		/* F7 */
140 #define USART_CR3_SCARCNT_MASK	GENMASK(19, 17)	/* F7 */
141 #define USART_CR3_WUS_MASK	GENMASK(21, 20)	/* H7 */
142 #define USART_CR3_WUS_START_BIT	BIT(21)		/* H7 */
143 #define USART_CR3_WUFIE		BIT(22)		/* H7 */
144 #define USART_CR3_TXFTIE	BIT(23)		/* H7 */
145 #define USART_CR3_TCBGTIE	BIT(24)		/* H7 */
146 #define USART_CR3_RXFTCFG_MASK	GENMASK(27, 25)	/* H7 */
147 #define USART_CR3_RXFTCFG_SHIFT	25		/* H7 */
148 #define USART_CR3_RXFTIE	BIT(28)		/* H7 */
149 #define USART_CR3_TXFTCFG_MASK	GENMASK(31, 29)	/* H7 */
150 #define USART_CR3_TXFTCFG_SHIFT	29		/* H7 */
151 
152 /* USART_GTPR */
153 #define USART_GTPR_PSC_MASK	GENMASK(7, 0)
154 #define USART_GTPR_GT_MASK	GENMASK(15, 8)
155 
156 /* USART_RTOR */
157 #define USART_RTOR_RTO_MASK	GENMASK(23, 0)	/* F7 */
158 #define USART_RTOR_BLEN_MASK	GENMASK(31, 24)	/* F7 */
159 
160 /* USART_RQR */
161 #define USART_RQR_ABRRQ		BIT(0)		/* F7 */
162 #define USART_RQR_SBKRQ		BIT(1)		/* F7 */
163 #define USART_RQR_MMRQ		BIT(2)		/* F7 */
164 #define USART_RQR_RXFRQ		BIT(3)		/* F7 */
165 #define USART_RQR_TXFRQ		BIT(4)		/* F7 */
166 
167 /* USART_ICR */
168 #define USART_ICR_PECF		BIT(0)		/* F7 */
169 #define USART_ICR_FECF		BIT(1)		/* F7 */
170 #define USART_ICR_ORECF		BIT(3)		/* F7 */
171 #define USART_ICR_IDLECF	BIT(4)		/* F7 */
172 #define USART_ICR_TCCF		BIT(6)		/* F7 */
173 #define USART_ICR_CTSCF		BIT(9)		/* F7 */
174 #define USART_ICR_RTOCF		BIT(11)		/* F7 */
175 #define USART_ICR_EOBCF		BIT(12)		/* F7 */
176 #define USART_ICR_CMCF		BIT(17)		/* F7 */
177 #define USART_ICR_WUCF		BIT(20)		/* H7 */
178 
179 #define STM32_SERIAL_NAME "ttySTM"
180 #define STM32_MAX_PORTS 8
181 
182 #define RX_BUF_L 4096		 /* dma rx buffer length     */
183 #define RX_BUF_P (RX_BUF_L / 2)	 /* dma rx buffer period     */
184 #define TX_BUF_L RX_BUF_L	 /* dma tx buffer length     */
185 
186 #define STM32_USART_TIMEOUT_USEC USEC_PER_SEC /* 1s timeout in µs */
187 
188 struct stm32_port {
189 	struct uart_port port;
190 	struct clk *clk;
191 	const struct stm32_usart_info *info;
192 	struct dma_chan *rx_ch;  /* dma rx channel            */
193 	dma_addr_t rx_dma_buf;   /* dma rx buffer bus address */
194 	unsigned char *rx_buf;   /* dma rx buffer cpu address */
195 	struct dma_chan *tx_ch;  /* dma tx channel            */
196 	dma_addr_t tx_dma_buf;   /* dma tx buffer bus address */
197 	unsigned char *tx_buf;   /* dma tx buffer cpu address */
198 	u32 cr1_irq;		 /* USART_CR1_RXNEIE or RTOIE */
199 	u32 cr3_irq;		 /* USART_CR3_RXFTIE */
200 	int last_res;
201 	bool tx_dma_busy;	 /* dma tx transaction in progress */
202 	bool rx_dma_busy;	 /* dma rx transaction in progress */
203 	bool throttled;		 /* port throttled            */
204 	bool hw_flow_control;
205 	bool swap;		 /* swap RX & TX pins */
206 	bool fifoen;
207 	int rxftcfg;		/* RX FIFO threshold CFG      */
208 	int txftcfg;		/* TX FIFO threshold CFG      */
209 	bool wakeup_src;
210 	int rdr_mask;		/* receive data register mask */
211 	struct mctrl_gpios *gpios; /* modem control gpios */
212 	struct dma_tx_state rx_dma_state;
213 };
214 
215 static struct stm32_port stm32_ports[STM32_MAX_PORTS];
216 static struct uart_driver stm32_usart_driver;
217