xref: /openbmc/linux/drivers/tty/serial/stm32-usart.h (revision 270e5a74fe4c78a857d65f1a129d3d77a36b8d58)
1 /*
2  * Copyright (C) Maxime Coquelin 2015
3  * Copyright (C) STMicroelectronics SA 2017
4  * Authors:  Maxime Coquelin <mcoquelin.stm32@gmail.com>
5  *	     Gerald Baeza <gerald_baeza@yahoo.fr>
6  * License terms:  GNU General Public License (GPL), version 2
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_wakeup;
29 };
30 
31 struct stm32_usart_info {
32 	struct stm32_usart_offsets ofs;
33 	struct stm32_usart_config cfg;
34 };
35 
36 #define UNDEF_REG 0xff
37 
38 /* Register offsets */
39 struct stm32_usart_info stm32f4_info = {
40 	.ofs = {
41 		.isr	= 0x00,
42 		.rdr	= 0x04,
43 		.tdr	= 0x04,
44 		.brr	= 0x08,
45 		.cr1	= 0x0c,
46 		.cr2	= 0x10,
47 		.cr3	= 0x14,
48 		.gtpr	= 0x18,
49 		.rtor	= UNDEF_REG,
50 		.rqr	= UNDEF_REG,
51 		.icr	= UNDEF_REG,
52 	},
53 	.cfg = {
54 		.uart_enable_bit = 13,
55 		.has_7bits_data = false,
56 	}
57 };
58 
59 struct stm32_usart_info stm32f7_info = {
60 	.ofs = {
61 		.cr1	= 0x00,
62 		.cr2	= 0x04,
63 		.cr3	= 0x08,
64 		.brr	= 0x0c,
65 		.gtpr	= 0x10,
66 		.rtor	= 0x14,
67 		.rqr	= 0x18,
68 		.isr	= 0x1c,
69 		.icr	= 0x20,
70 		.rdr	= 0x24,
71 		.tdr	= 0x28,
72 	},
73 	.cfg = {
74 		.uart_enable_bit = 0,
75 		.has_7bits_data = true,
76 	}
77 };
78 
79 struct stm32_usart_info stm32h7_info = {
80 	.ofs = {
81 		.cr1	= 0x00,
82 		.cr2	= 0x04,
83 		.cr3	= 0x08,
84 		.brr	= 0x0c,
85 		.gtpr	= 0x10,
86 		.rtor	= 0x14,
87 		.rqr	= 0x18,
88 		.isr	= 0x1c,
89 		.icr	= 0x20,
90 		.rdr	= 0x24,
91 		.tdr	= 0x28,
92 	},
93 	.cfg = {
94 		.uart_enable_bit = 0,
95 		.has_7bits_data = true,
96 		.has_wakeup = true,
97 	}
98 };
99 
100 /* USART_SR (F4) / USART_ISR (F7) */
101 #define USART_SR_PE		BIT(0)
102 #define USART_SR_FE		BIT(1)
103 #define USART_SR_NF		BIT(2)
104 #define USART_SR_ORE		BIT(3)
105 #define USART_SR_IDLE		BIT(4)
106 #define USART_SR_RXNE		BIT(5)
107 #define USART_SR_TC		BIT(6)
108 #define USART_SR_TXE		BIT(7)
109 #define USART_SR_LBD		BIT(8)
110 #define USART_SR_CTSIF		BIT(9)
111 #define USART_SR_CTS		BIT(10)		/* F7 */
112 #define USART_SR_RTOF		BIT(11)		/* F7 */
113 #define USART_SR_EOBF		BIT(12)		/* F7 */
114 #define USART_SR_ABRE		BIT(14)		/* F7 */
115 #define USART_SR_ABRF		BIT(15)		/* F7 */
116 #define USART_SR_BUSY		BIT(16)		/* F7 */
117 #define USART_SR_CMF		BIT(17)		/* F7 */
118 #define USART_SR_SBKF		BIT(18)		/* F7 */
119 #define USART_SR_WUF		BIT(20)		/* H7 */
120 #define USART_SR_TEACK		BIT(21)		/* F7 */
121 #define USART_SR_ERR_MASK	(USART_SR_LBD | USART_SR_ORE | \
122 				 USART_SR_FE | USART_SR_PE)
123 /* Dummy bits */
124 #define USART_SR_DUMMY_RX	BIT(16)
125 
126 /* USART_ICR (F7) */
127 #define USART_CR_TC		BIT(6)
128 
129 /* USART_DR */
130 #define USART_DR_MASK		GENMASK(8, 0)
131 
132 /* USART_BRR */
133 #define USART_BRR_DIV_F_MASK	GENMASK(3, 0)
134 #define USART_BRR_DIV_M_MASK	GENMASK(15, 4)
135 #define USART_BRR_DIV_M_SHIFT	4
136 
137 /* USART_CR1 */
138 #define USART_CR1_SBK		BIT(0)
139 #define USART_CR1_RWU		BIT(1)		/* F4 */
140 #define USART_CR1_UESM		BIT(1)		/* H7 */
141 #define USART_CR1_RE		BIT(2)
142 #define USART_CR1_TE		BIT(3)
143 #define USART_CR1_IDLEIE	BIT(4)
144 #define USART_CR1_RXNEIE	BIT(5)
145 #define USART_CR1_TCIE		BIT(6)
146 #define USART_CR1_TXEIE		BIT(7)
147 #define USART_CR1_PEIE		BIT(8)
148 #define USART_CR1_PS		BIT(9)
149 #define USART_CR1_PCE		BIT(10)
150 #define USART_CR1_WAKE		BIT(11)
151 #define USART_CR1_M		BIT(12)
152 #define USART_CR1_M0		BIT(12)		/* F7 */
153 #define USART_CR1_MME		BIT(13)		/* F7 */
154 #define USART_CR1_CMIE		BIT(14)		/* F7 */
155 #define USART_CR1_OVER8		BIT(15)
156 #define USART_CR1_DEDT_MASK	GENMASK(20, 16)	/* F7 */
157 #define USART_CR1_DEAT_MASK	GENMASK(25, 21)	/* F7 */
158 #define USART_CR1_RTOIE		BIT(26)		/* F7 */
159 #define USART_CR1_EOBIE		BIT(27)		/* F7 */
160 #define USART_CR1_M1		BIT(28)		/* F7 */
161 #define USART_CR1_IE_MASK	(GENMASK(8, 4) | BIT(14) | BIT(26) | BIT(27))
162 
163 /* USART_CR2 */
164 #define USART_CR2_ADD_MASK	GENMASK(3, 0)	/* F4 */
165 #define USART_CR2_ADDM7		BIT(4)		/* F7 */
166 #define USART_CR2_LBDL		BIT(5)
167 #define USART_CR2_LBDIE		BIT(6)
168 #define USART_CR2_LBCL		BIT(8)
169 #define USART_CR2_CPHA		BIT(9)
170 #define USART_CR2_CPOL		BIT(10)
171 #define USART_CR2_CLKEN		BIT(11)
172 #define USART_CR2_STOP_2B	BIT(13)
173 #define USART_CR2_STOP_MASK	GENMASK(13, 12)
174 #define USART_CR2_LINEN		BIT(14)
175 #define USART_CR2_SWAP		BIT(15)		/* F7 */
176 #define USART_CR2_RXINV		BIT(16)		/* F7 */
177 #define USART_CR2_TXINV		BIT(17)		/* F7 */
178 #define USART_CR2_DATAINV	BIT(18)		/* F7 */
179 #define USART_CR2_MSBFIRST	BIT(19)		/* F7 */
180 #define USART_CR2_ABREN		BIT(20)		/* F7 */
181 #define USART_CR2_ABRMOD_MASK	GENMASK(22, 21)	/* F7 */
182 #define USART_CR2_RTOEN		BIT(23)		/* F7 */
183 #define USART_CR2_ADD_F7_MASK	GENMASK(31, 24)	/* F7 */
184 
185 /* USART_CR3 */
186 #define USART_CR3_EIE		BIT(0)
187 #define USART_CR3_IREN		BIT(1)
188 #define USART_CR3_IRLP		BIT(2)
189 #define USART_CR3_HDSEL		BIT(3)
190 #define USART_CR3_NACK		BIT(4)
191 #define USART_CR3_SCEN		BIT(5)
192 #define USART_CR3_DMAR		BIT(6)
193 #define USART_CR3_DMAT		BIT(7)
194 #define USART_CR3_RTSE		BIT(8)
195 #define USART_CR3_CTSE		BIT(9)
196 #define USART_CR3_CTSIE		BIT(10)
197 #define USART_CR3_ONEBIT	BIT(11)
198 #define USART_CR3_OVRDIS	BIT(12)		/* F7 */
199 #define USART_CR3_DDRE		BIT(13)		/* F7 */
200 #define USART_CR3_DEM		BIT(14)		/* F7 */
201 #define USART_CR3_DEP		BIT(15)		/* F7 */
202 #define USART_CR3_SCARCNT_MASK	GENMASK(19, 17)	/* F7 */
203 #define USART_CR3_WUS_MASK	GENMASK(21, 20)	/* H7 */
204 #define USART_CR3_WUS_START_BIT	BIT(21)		/* H7 */
205 #define USART_CR3_WUFIE		BIT(22)		/* H7 */
206 
207 /* USART_GTPR */
208 #define USART_GTPR_PSC_MASK	GENMASK(7, 0)
209 #define USART_GTPR_GT_MASK	GENMASK(15, 8)
210 
211 /* USART_RTOR */
212 #define USART_RTOR_RTO_MASK	GENMASK(23, 0)	/* F7 */
213 #define USART_RTOR_BLEN_MASK	GENMASK(31, 24)	/* F7 */
214 
215 /* USART_RQR */
216 #define USART_RQR_ABRRQ		BIT(0)		/* F7 */
217 #define USART_RQR_SBKRQ		BIT(1)		/* F7 */
218 #define USART_RQR_MMRQ		BIT(2)		/* F7 */
219 #define USART_RQR_RXFRQ		BIT(3)		/* F7 */
220 #define USART_RQR_TXFRQ		BIT(4)		/* F7 */
221 
222 /* USART_ICR */
223 #define USART_ICR_PECF		BIT(0)		/* F7 */
224 #define USART_ICR_FFECF		BIT(1)		/* F7 */
225 #define USART_ICR_NCF		BIT(2)		/* F7 */
226 #define USART_ICR_ORECF		BIT(3)		/* F7 */
227 #define USART_ICR_IDLECF	BIT(4)		/* F7 */
228 #define USART_ICR_TCCF		BIT(6)		/* F7 */
229 #define USART_ICR_LBDCF		BIT(8)		/* F7 */
230 #define USART_ICR_CTSCF		BIT(9)		/* F7 */
231 #define USART_ICR_RTOCF		BIT(11)		/* F7 */
232 #define USART_ICR_EOBCF		BIT(12)		/* F7 */
233 #define USART_ICR_CMCF		BIT(17)		/* F7 */
234 #define USART_ICR_WUCF		BIT(20)		/* H7 */
235 
236 #define STM32_SERIAL_NAME "ttyS"
237 #define STM32_MAX_PORTS 8
238 
239 #define RX_BUF_L 200		 /* dma rx buffer length     */
240 #define RX_BUF_P RX_BUF_L	 /* dma rx buffer period     */
241 #define TX_BUF_L 200		 /* dma tx buffer length     */
242 
243 struct stm32_port {
244 	struct uart_port port;
245 	struct clk *clk;
246 	struct stm32_usart_info *info;
247 	struct dma_chan *rx_ch;  /* dma rx channel            */
248 	dma_addr_t rx_dma_buf;   /* dma rx buffer bus address */
249 	unsigned char *rx_buf;   /* dma rx buffer cpu address */
250 	struct dma_chan *tx_ch;  /* dma tx channel            */
251 	dma_addr_t tx_dma_buf;   /* dma tx buffer bus address */
252 	unsigned char *tx_buf;   /* dma tx buffer cpu address */
253 	int last_res;
254 	bool tx_dma_busy;	 /* dma tx busy               */
255 	bool hw_flow_control;
256 	int wakeirq;
257 };
258 
259 static struct stm32_port stm32_ports[STM32_MAX_PORTS];
260 static struct uart_driver stm32_usart_driver;
261