summaryrefslogtreecommitdiffstats
path: root/drivers/tty/serial/stm32-usart.h
blob: af20258ccc7a0fcc57a541b37efcc9848290e141 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (C) Maxime Coquelin 2015
 * Copyright (C) STMicroelectronics SA 2017
 * Authors:  Maxime Coquelin <mcoquelin.stm32@gmail.com>
 *	     Gerald Baeza <gerald_baeza@yahoo.fr>
 */

#define DRIVER_NAME "stm32-usart"

struct stm32_usart_offsets {
	u16 cr1;
	u16 cr2;
	u16 cr3;
	u16 brr;
	u16 gtpr;
	u16 rtor;
	u16 rqr;
	u16 isr;
	u16 icr;
	u16 rdr;
	u16 tdr;
	u16 presc;
	u16 hwcfgr1;
};

struct stm32_usart_config {
	u8 uart_enable_bit; /* USART_CR1_UE */
	bool has_7bits_data;
	bool has_swap;
	bool has_wakeup;
	bool has_fifo;
};

struct stm32_usart_info {
	struct stm32_usart_offsets ofs;
	struct stm32_usart_config cfg;
};

#define UNDEF_REG 0xffff

/* USART_SR (F4) / USART_ISR (F7) */
#define USART_SR_PE		BIT(0)
#define USART_SR_FE		BIT(1)
#define USART_SR_NE		BIT(2)		/* F7 (NF for F4) */
#define USART_SR_ORE		BIT(3)
#define USART_SR_IDLE		BIT(4)
#define USART_SR_RXNE		BIT(5)
#define USART_SR_TC		BIT(6)
#define USART_SR_TXE		BIT(7)
#define USART_SR_CTSIF		BIT(9)
#define USART_SR_CTS		BIT(10)		/* F7 */
#define USART_SR_RTOF		BIT(11)		/* F7 */
#define USART_SR_EOBF		BIT(12)		/* F7 */
#define USART_SR_ABRE		BIT(14)		/* F7 */
#define USART_SR_ABRF		BIT(15)		/* F7 */
#define USART_SR_BUSY		BIT(16)		/* F7 */
#define USART_SR_CMF		BIT(17)		/* F7 */
#define USART_SR_SBKF		BIT(18)		/* F7 */
#define USART_SR_WUF		BIT(20)		/* H7 */
#define USART_SR_TEACK		BIT(21)		/* F7 */
#define USART_SR_ERR_MASK	(USART_SR_ORE | USART_SR_NE | USART_SR_FE |\
				 USART_SR_PE)
/* Dummy bits */
#define USART_SR_DUMMY_RX	BIT(16)

/* USART_DR */
#define USART_DR_MASK		GENMASK(8, 0)

/* USART_BRR */
#define USART_BRR_DIV_F_MASK	GENMASK(3, 0)
#define USART_BRR_DIV_M_MASK	GENMASK(15, 4)
#define USART_BRR_DIV_M_SHIFT	4
#define USART_BRR_04_R_SHIFT	1
#define USART_BRR_MASK		(USART_BRR_DIV_M_MASK | USART_BRR_DIV_F_MASK)

/* USART_CR1 */
#define USART_CR1_SBK		BIT(0)
#define USART_CR1_RWU		BIT(1)		/* F4 */
#define USART_CR1_UESM		BIT(1)		/* H7 */
#define USART_CR1_RE		BIT(2)
#define USART_CR1_TE		BIT(3)
#define USART_CR1_IDLEIE	BIT(4)
#define USART_CR1_RXNEIE	BIT(5)
#define USART_CR1_TCIE		BIT(6)
#define USART_CR1_TXEIE		BIT(7)
#define USART_CR1_PEIE		BIT(8)
#define USART_CR1_PS		BIT(9)
#define USART_CR1_PCE		BIT(10)
#define USART_CR1_WAKE		BIT(11)
#define USART_CR1_M0		BIT(12)		/* F7 (CR1_M for F4) */
#define USART_CR1_MME		BIT(13)		/* F7 */
#define USART_CR1_CMIE		BIT(14)		/* F7 */
#define USART_CR1_OVER8		BIT(15)
#define USART_CR1_DEDT_MASK	GENMASK(20, 16)	/* F7 */
#define USART_CR1_DEAT_MASK	GENMASK(25, 21)	/* F7 */
#define USART_CR1_RTOIE		BIT(26)		/* F7 */
#define USART_CR1_EOBIE		BIT(27)		/* F7 */
#define USART_CR1_M1		BIT(28)		/* F7 */
#define USART_CR1_IE_MASK	(GENMASK(8, 4) | BIT(14) | BIT(26) | BIT(27))
#define USART_CR1_FIFOEN	BIT(29)		/* H7 */
#define USART_CR1_DEAT_SHIFT 21
#define USART_CR1_DEDT_SHIFT 16

/* USART_CR2 */
#define USART_CR2_ADD_MASK	GENMASK(3, 0)	/* F4 */
#define USART_CR2_ADDM7		BIT(4)		/* F7 */
#define USART_CR2_LBCL		BIT(8)
#define USART_CR2_CPHA		BIT(9)
#define USART_CR2_CPOL		BIT(10)
#define USART_CR2_CLKEN		BIT(11)
#define USART_CR2_STOP_2B	BIT(13)
#define USART_CR2_STOP_MASK	GENMASK(13, 12)
#define USART_CR2_LINEN		BIT(14)
#define USART_CR2_SWAP		BIT(15)		/* F7 */
#define USART_CR2_RXINV		BIT(16)		/* F7 */
#define USART_CR2_TXINV		BIT(17)		/* F7 */
#define USART_CR2_DATAINV	BIT(18)		/* F7 */
#define USART_CR2_MSBFIRST	BIT(19)		/* F7 */
#define USART_CR2_ABREN		BIT(20)		/* F7 */
#define USART_CR2_ABRMOD_MASK	GENMASK(22, 21)	/* F7 */
#define USART_CR2_RTOEN		BIT(23)		/* F7 */
#define USART_CR2_ADD_F7_MASK	GENMASK(31, 24)	/* F7 */

/* USART_CR3 */
#define USART_CR3_EIE		BIT(0)
#define USART_CR3_IREN		BIT(1)
#define USART_CR3_IRLP		BIT(2)
#define USART_CR3_HDSEL		BIT(3)
#define USART_CR3_NACK		BIT(4)
#define USART_CR3_SCEN		BIT(5)
#define USART_CR3_DMAR		BIT(6)
#define USART_CR3_DMAT		BIT(7)
#define USART_CR3_RTSE		BIT(8)
#define USART_CR3_CTSE		BIT(9)
#define USART_CR3_CTSIE		BIT(10)
#define USART_CR3_ONEBIT	BIT(11)
#define USART_CR3_OVRDIS	BIT(12)		/* F7 */
#define USART_CR3_DDRE		BIT(13)		/* F7 */
#define USART_CR3_DEM		BIT(14)		/* F7 */
#define USART_CR3_DEP		BIT(15)		/* F7 */
#define USART_CR3_SCARCNT_MASK	GENMASK(19, 17)	/* F7 */
#define USART_CR3_WUS_MASK	GENMASK(21, 20)	/* H7 */
#define USART_CR3_WUS_START_BIT	BIT(21)		/* H7 */
#define USART_CR3_WUFIE		BIT(22)		/* H7 */
#define USART_CR3_TXFTIE	BIT(23)		/* H7 */
#define USART_CR3_TCBGTIE	BIT(24)		/* H7 */
#define USART_CR3_RXFTCFG_MASK	GENMASK(27, 25)	/* H7 */
#define USART_CR3_RXFTCFG_SHIFT	25		/* H7 */
#define USART_CR3_RXFTIE	BIT(28)		/* H7 */
#define USART_CR3_TXFTCFG_MASK	GENMASK(31, 29)	/* H7 */
#define USART_CR3_TXFTCFG_SHIFT	29		/* H7 */

/* USART_GTPR */
#define USART_GTPR_PSC_MASK	GENMASK(7, 0)
#define USART_GTPR_GT_MASK	GENMASK(15, 8)

/* USART_RTOR */
#define USART_RTOR_RTO_MASK	GENMASK(23, 0)	/* F7 */
#define USART_RTOR_BLEN_MASK	GENMASK(31, 24)	/* F7 */

/* USART_RQR */
#define USART_RQR_ABRRQ		BIT(0)		/* F7 */
#define USART_RQR_SBKRQ		BIT(1)		/* F7 */
#define USART_RQR_MMRQ		BIT(2)		/* F7 */
#define USART_RQR_RXFRQ		BIT(3)		/* F7 */
#define USART_RQR_TXFRQ		BIT(4)		/* F7 */

/* USART_ICR */
#define USART_ICR_PECF		BIT(0)		/* F7 */
#define USART_ICR_FECF		BIT(1)		/* F7 */
#define USART_ICR_ORECF		BIT(3)		/* F7 */
#define USART_ICR_IDLECF	BIT(4)		/* F7 */
#define USART_ICR_TCCF		BIT(6)		/* F7 */
#define USART_ICR_CTSCF		BIT(9)		/* F7 */
#define USART_ICR_RTOCF		BIT(11)		/* F7 */
#define USART_ICR_EOBCF		BIT(12)		/* F7 */
#define USART_ICR_CMCF		BIT(17)		/* F7 */
#define USART_ICR_WUCF		BIT(20)		/* H7 */

/* USART_PRESC */
#define USART_PRESC		GENMASK(3, 0)	/* H7 */
#define USART_PRESC_MAX		0b1011

/* USART_HWCFCR1 */
#define USART_HWCFGR1_CFG8	GENMASK(31, 28)	/* MP1 */

#define STM32_SERIAL_NAME "ttySTM"
#define STM32_MAX_PORTS 9
#define STM32H7_USART_FIFO_SIZE 16

#define RX_BUF_L 4096		 /* dma rx buffer length     */
#define RX_BUF_P (RX_BUF_L / 2)	 /* dma rx buffer period     */
#define TX_BUF_L RX_BUF_L	 /* dma tx buffer length     */

#define STM32_USART_TIMEOUT_USEC USEC_PER_SEC /* 1s timeout in µs */

struct stm32_port {
	struct uart_port port;
	struct clk *clk;
	const struct stm32_usart_info *info;
	struct dma_chan *rx_ch;  /* dma rx channel            */
	dma_addr_t rx_dma_buf;   /* dma rx buffer bus address */
	unsigned char *rx_buf;   /* dma rx buffer cpu address */
	struct dma_chan *tx_ch;  /* dma tx channel            */
	dma_addr_t tx_dma_buf;   /* dma tx buffer bus address */
	unsigned char *tx_buf;   /* dma tx buffer cpu address */
	u32 cr1_irq;		 /* USART_CR1_RXNEIE or RTOIE */
	u32 cr3_irq;		 /* USART_CR3_RXFTIE */
	int last_res;
	bool tx_dma_busy;	 /* dma tx transaction in progress */
	bool rx_dma_busy;	 /* dma rx transaction in progress */
	bool throttled;		 /* port throttled            */
	bool hw_flow_control;
	bool swap;		 /* swap RX & TX pins */
	bool fifoen;
	int rxftcfg;		/* RX FIFO threshold CFG      */
	int txftcfg;		/* TX FIFO threshold CFG      */
	bool wakeup_src;
	int rdr_mask;		/* receive data register mask */
	struct mctrl_gpios *gpios; /* modem control gpios */
	struct dma_tx_state rx_dma_state;
};

static struct stm32_port stm32_ports[STM32_MAX_PORTS];
static struct uart_driver stm32_usart_driver;