xref: /openbmc/linux/drivers/tty/serial/stm32-usart.h (revision e5c86679) 
1 /*
2  * Copyright (C) Maxime Coquelin 2015
3  * Authors:  Maxime Coquelin <mcoquelin.stm32@gmail.com>
4  *	     Gerald Baeza <gerald_baeza@yahoo.fr>
5  * License terms:  GNU General Public License (GPL), version 2
6  */
7 
8 #define DRIVER_NAME "stm32-usart"
9 
10 struct stm32_usart_offsets {
11 	u8 cr1;
12 	u8 cr2;
13 	u8 cr3;
14 	u8 brr;
15 	u8 gtpr;
16 	u8 rtor;
17 	u8 rqr;
18 	u8 isr;
19 	u8 icr;
20 	u8 rdr;
21 	u8 tdr;
22 };
23 
24 struct stm32_usart_config {
25 	u8 uart_enable_bit; /* USART_CR1_UE */
26 	bool has_7bits_data;
27 };
28 
29 struct stm32_usart_info {
30 	struct stm32_usart_offsets ofs;
31 	struct stm32_usart_config cfg;
32 };
33 
34 #define UNDEF_REG 0xff
35 
36 /* Register offsets */
37 struct stm32_usart_info stm32f4_info = {
38 	.ofs = {
39 		.isr	= 0x00,
40 		.rdr	= 0x04,
41 		.tdr	= 0x04,
42 		.brr	= 0x08,
43 		.cr1	= 0x0c,
44 		.cr2	= 0x10,
45 		.cr3	= 0x14,
46 		.gtpr	= 0x18,
47 		.rtor	= UNDEF_REG,
48 		.rqr	= UNDEF_REG,
49 		.icr	= UNDEF_REG,
50 	},
51 	.cfg = {
52 		.uart_enable_bit = 13,
53 		.has_7bits_data = false,
54 	}
55 };
56 
57 struct stm32_usart_info stm32f7_info = {
58 	.ofs = {
59 		.cr1	= 0x00,
60 		.cr2	= 0x04,
61 		.cr3	= 0x08,
62 		.brr	= 0x0c,
63 		.gtpr	= 0x10,
64 		.rtor	= 0x14,
65 		.rqr	= 0x18,
66 		.isr	= 0x1c,
67 		.icr	= 0x20,
68 		.rdr	= 0x24,
69 		.tdr	= 0x28,
70 	},
71 	.cfg = {
72 		.uart_enable_bit = 0,
73 		.has_7bits_data = true,
74 	}
75 };
76 
77 /* USART_SR (F4) / USART_ISR (F7) */
78 #define USART_SR_PE		BIT(0)
79 #define USART_SR_FE		BIT(1)
80 #define USART_SR_NF		BIT(2)
81 #define USART_SR_ORE		BIT(3)
82 #define USART_SR_IDLE		BIT(4)
83 #define USART_SR_RXNE		BIT(5)
84 #define USART_SR_TC		BIT(6)
85 #define USART_SR_TXE		BIT(7)
86 #define USART_SR_LBD		BIT(8)
87 #define USART_SR_CTSIF		BIT(9)
88 #define USART_SR_CTS		BIT(10)		/* F7 */
89 #define USART_SR_RTOF		BIT(11)		/* F7 */
90 #define USART_SR_EOBF		BIT(12)		/* F7 */
91 #define USART_SR_ABRE		BIT(14)		/* F7 */
92 #define USART_SR_ABRF		BIT(15)		/* F7 */
93 #define USART_SR_BUSY		BIT(16)		/* F7 */
94 #define USART_SR_CMF		BIT(17)		/* F7 */
95 #define USART_SR_SBKF		BIT(18)		/* F7 */
96 #define USART_SR_TEACK		BIT(21)		/* F7 */
97 #define USART_SR_ERR_MASK	(USART_SR_LBD | USART_SR_ORE | \
98 				 USART_SR_FE | USART_SR_PE)
99 /* Dummy bits */
100 #define USART_SR_DUMMY_RX	BIT(16)
101 
102 /* USART_ICR (F7) */
103 #define USART_CR_TC		BIT(6)
104 
105 /* USART_DR */
106 #define USART_DR_MASK		GENMASK(8, 0)
107 
108 /* USART_BRR */
109 #define USART_BRR_DIV_F_MASK	GENMASK(3, 0)
110 #define USART_BRR_DIV_M_MASK	GENMASK(15, 4)
111 #define USART_BRR_DIV_M_SHIFT	4
112 
113 /* USART_CR1 */
114 #define USART_CR1_SBK		BIT(0)
115 #define USART_CR1_RWU		BIT(1)		/* F4 */
116 #define USART_CR1_RE		BIT(2)
117 #define USART_CR1_TE		BIT(3)
118 #define USART_CR1_IDLEIE	BIT(4)
119 #define USART_CR1_RXNEIE	BIT(5)
120 #define USART_CR1_TCIE		BIT(6)
121 #define USART_CR1_TXEIE		BIT(7)
122 #define USART_CR1_PEIE		BIT(8)
123 #define USART_CR1_PS		BIT(9)
124 #define USART_CR1_PCE		BIT(10)
125 #define USART_CR1_WAKE		BIT(11)
126 #define USART_CR1_M		BIT(12)
127 #define USART_CR1_M0		BIT(12)		/* F7 */
128 #define USART_CR1_MME		BIT(13)		/* F7 */
129 #define USART_CR1_CMIE		BIT(14)		/* F7 */
130 #define USART_CR1_OVER8		BIT(15)
131 #define USART_CR1_DEDT_MASK	GENMASK(20, 16)	/* F7 */
132 #define USART_CR1_DEAT_MASK	GENMASK(25, 21)	/* F7 */
133 #define USART_CR1_RTOIE		BIT(26)		/* F7 */
134 #define USART_CR1_EOBIE		BIT(27)		/* F7 */
135 #define USART_CR1_M1		BIT(28)		/* F7 */
136 #define USART_CR1_IE_MASK	(GENMASK(8, 4) | BIT(14) | BIT(26) | BIT(27))
137 
138 /* USART_CR2 */
139 #define USART_CR2_ADD_MASK	GENMASK(3, 0)	/* F4 */
140 #define USART_CR2_ADDM7		BIT(4)		/* F7 */
141 #define USART_CR2_LBDL		BIT(5)
142 #define USART_CR2_LBDIE		BIT(6)
143 #define USART_CR2_LBCL		BIT(8)
144 #define USART_CR2_CPHA		BIT(9)
145 #define USART_CR2_CPOL		BIT(10)
146 #define USART_CR2_CLKEN		BIT(11)
147 #define USART_CR2_STOP_2B	BIT(13)
148 #define USART_CR2_STOP_MASK	GENMASK(13, 12)
149 #define USART_CR2_LINEN		BIT(14)
150 #define USART_CR2_SWAP		BIT(15)		/* F7 */
151 #define USART_CR2_RXINV		BIT(16)		/* F7 */
152 #define USART_CR2_TXINV		BIT(17)		/* F7 */
153 #define USART_CR2_DATAINV	BIT(18)		/* F7 */
154 #define USART_CR2_MSBFIRST	BIT(19)		/* F7 */
155 #define USART_CR2_ABREN		BIT(20)		/* F7 */
156 #define USART_CR2_ABRMOD_MASK	GENMASK(22, 21)	/* F7 */
157 #define USART_CR2_RTOEN		BIT(23)		/* F7 */
158 #define USART_CR2_ADD_F7_MASK	GENMASK(31, 24)	/* F7 */
159 
160 /* USART_CR3 */
161 #define USART_CR3_EIE		BIT(0)
162 #define USART_CR3_IREN		BIT(1)
163 #define USART_CR3_IRLP		BIT(2)
164 #define USART_CR3_HDSEL		BIT(3)
165 #define USART_CR3_NACK		BIT(4)
166 #define USART_CR3_SCEN		BIT(5)
167 #define USART_CR3_DMAR		BIT(6)
168 #define USART_CR3_DMAT		BIT(7)
169 #define USART_CR3_RTSE		BIT(8)
170 #define USART_CR3_CTSE		BIT(9)
171 #define USART_CR3_CTSIE		BIT(10)
172 #define USART_CR3_ONEBIT	BIT(11)
173 #define USART_CR3_OVRDIS	BIT(12)		/* F7 */
174 #define USART_CR3_DDRE		BIT(13)		/* F7 */
175 #define USART_CR3_DEM		BIT(14)		/* F7 */
176 #define USART_CR3_DEP		BIT(15)		/* F7 */
177 #define USART_CR3_SCARCNT_MASK	GENMASK(19, 17)	/* F7 */
178 
179 /* USART_GTPR */
180 #define USART_GTPR_PSC_MASK	GENMASK(7, 0)
181 #define USART_GTPR_GT_MASK	GENMASK(15, 8)
182 
183 /* USART_RTOR */
184 #define USART_RTOR_RTO_MASK	GENMASK(23, 0)	/* F7 */
185 #define USART_RTOR_BLEN_MASK	GENMASK(31, 24)	/* F7 */
186 
187 /* USART_RQR */
188 #define USART_RQR_ABRRQ		BIT(0)		/* F7 */
189 #define USART_RQR_SBKRQ		BIT(1)		/* F7 */
190 #define USART_RQR_MMRQ		BIT(2)		/* F7 */
191 #define USART_RQR_RXFRQ		BIT(3)		/* F7 */
192 #define USART_RQR_TXFRQ		BIT(4)		/* F7 */
193 
194 /* USART_ICR */
195 #define USART_ICR_PECF		BIT(0)		/* F7 */
196 #define USART_ICR_FFECF		BIT(1)		/* F7 */
197 #define USART_ICR_NCF		BIT(2)		/* F7 */
198 #define USART_ICR_ORECF		BIT(3)		/* F7 */
199 #define USART_ICR_IDLECF	BIT(4)		/* F7 */
200 #define USART_ICR_TCCF		BIT(6)		/* F7 */
201 #define USART_ICR_LBDCF		BIT(8)		/* F7 */
202 #define USART_ICR_CTSCF		BIT(9)		/* F7 */
203 #define USART_ICR_RTOCF		BIT(11)		/* F7 */
204 #define USART_ICR_EOBCF		BIT(12)		/* F7 */
205 #define USART_ICR_CMCF		BIT(17)		/* F7 */
206 
207 #define STM32_SERIAL_NAME "ttyS"
208 #define STM32_MAX_PORTS 6
209 
210 #define RX_BUF_L 200		 /* dma rx buffer length     */
211 #define RX_BUF_P RX_BUF_L	 /* dma rx buffer period     */
212 #define TX_BUF_L 200		 /* dma tx buffer length     */
213 
214 struct stm32_port {
215 	struct uart_port port;
216 	struct clk *clk;
217 	struct stm32_usart_info *info;
218 	struct dma_chan *rx_ch;  /* dma rx channel            */
219 	dma_addr_t rx_dma_buf;   /* dma rx buffer bus address */
220 	unsigned char *rx_buf;   /* dma rx buffer cpu address */
221 	struct dma_chan *tx_ch;  /* dma tx channel            */
222 	dma_addr_t tx_dma_buf;   /* dma tx buffer bus address */
223 	unsigned char *tx_buf;   /* dma tx buffer cpu address */
224 	bool tx_dma_busy;	 /* dma tx busy               */
225 	bool hw_flow_control;
226 };
227 
228 static struct stm32_port stm32_ports[STM32_MAX_PORTS];
229 static struct uart_driver stm32_usart_driver;
230