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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
11struct stm32_usart_offsets {
12 u16 cr1;
13 u16 cr2;
14 u16 cr3;
15 u16 brr;
16 u16 gtpr;
17 u16 rtor;
18 u16 rqr;
19 u16 isr;
20 u16 icr;
21 u16 rdr;
22 u16 tdr;
23 u16 presc;
24 u16 hwcfgr1;
25};
26
27struct stm32_usart_config {
28 u8 uart_enable_bit; /* USART_CR1_UE */
29 bool has_7bits_data;
30 bool has_swap;
31 bool has_wakeup;
32 bool has_fifo;
33};
34
35struct stm32_usart_info {
36 struct stm32_usart_offsets ofs;
37 struct stm32_usart_config cfg;
38};
39
40#define UNDEF_REG 0xffff
41
42/* USART_SR (F4) / USART_ISR (F7) */
43#define USART_SR_PE BIT(0)
44#define USART_SR_FE BIT(1)
45#define USART_SR_NE BIT(2) /* F7 (NF for F4) */
46#define USART_SR_ORE BIT(3)
47#define USART_SR_IDLE BIT(4)
48#define USART_SR_RXNE BIT(5)
49#define USART_SR_TC BIT(6)
50#define USART_SR_TXE BIT(7)
51#define USART_SR_CTSIF BIT(9)
52#define USART_SR_CTS BIT(10) /* F7 */
53#define USART_SR_RTOF BIT(11) /* F7 */
54#define USART_SR_EOBF BIT(12) /* F7 */
55#define USART_SR_ABRE BIT(14) /* F7 */
56#define USART_SR_ABRF BIT(15) /* F7 */
57#define USART_SR_BUSY BIT(16) /* F7 */
58#define USART_SR_CMF BIT(17) /* F7 */
59#define USART_SR_SBKF BIT(18) /* F7 */
60#define USART_SR_WUF BIT(20) /* H7 */
61#define USART_SR_TEACK BIT(21) /* F7 */
62#define USART_SR_ERR_MASK (USART_SR_ORE | USART_SR_NE | USART_SR_FE |\
63 USART_SR_PE)
64/* Dummy bits */
65#define USART_SR_DUMMY_RX BIT(16)
66
67/* USART_DR */
68#define USART_DR_MASK GENMASK(8, 0)
69
70/* USART_BRR */
71#define USART_BRR_DIV_F_MASK GENMASK(3, 0)
72#define USART_BRR_DIV_M_MASK GENMASK(15, 4)
73#define USART_BRR_DIV_M_SHIFT 4
74#define USART_BRR_04_R_SHIFT 1
75#define USART_BRR_MASK (USART_BRR_DIV_M_MASK | USART_BRR_DIV_F_MASK)
76
77/* USART_CR1 */
78#define USART_CR1_SBK BIT(0)
79#define USART_CR1_RWU BIT(1) /* F4 */
80#define USART_CR1_UESM BIT(1) /* H7 */
81#define USART_CR1_RE BIT(2)
82#define USART_CR1_TE BIT(3)
83#define USART_CR1_IDLEIE BIT(4)
84#define USART_CR1_RXNEIE BIT(5)
85#define USART_CR1_TCIE BIT(6)
86#define USART_CR1_TXEIE BIT(7)
87#define USART_CR1_PEIE BIT(8)
88#define USART_CR1_PS BIT(9)
89#define USART_CR1_PCE BIT(10)
90#define USART_CR1_WAKE BIT(11)
91#define USART_CR1_M0 BIT(12) /* F7 (CR1_M for F4) */
92#define USART_CR1_MME BIT(13) /* F7 */
93#define USART_CR1_CMIE BIT(14) /* F7 */
94#define USART_CR1_OVER8 BIT(15)
95#define USART_CR1_DEDT_MASK GENMASK(20, 16) /* F7 */
96#define USART_CR1_DEAT_MASK GENMASK(25, 21) /* F7 */
97#define USART_CR1_RTOIE BIT(26) /* F7 */
98#define USART_CR1_EOBIE BIT(27) /* F7 */
99#define USART_CR1_M1 BIT(28) /* F7 */
100#define USART_CR1_IE_MASK (GENMASK(8, 4) | BIT(14) | BIT(26) | BIT(27))
101#define USART_CR1_FIFOEN BIT(29) /* H7 */
102#define USART_CR1_DEAT_SHIFT 21
103#define USART_CR1_DEDT_SHIFT 16
104
105/* USART_CR2 */
106#define USART_CR2_ADD_MASK GENMASK(3, 0) /* F4 */
107#define USART_CR2_ADDM7 BIT(4) /* F7 */
108#define USART_CR2_LBCL BIT(8)
109#define USART_CR2_CPHA BIT(9)
110#define USART_CR2_CPOL BIT(10)
111#define USART_CR2_CLKEN BIT(11)
112#define USART_CR2_STOP_2B BIT(13)
113#define USART_CR2_STOP_MASK GENMASK(13, 12)
114#define USART_CR2_LINEN BIT(14)
115#define USART_CR2_SWAP BIT(15) /* F7 */
116#define USART_CR2_RXINV BIT(16) /* F7 */
117#define USART_CR2_TXINV BIT(17) /* F7 */
118#define USART_CR2_DATAINV BIT(18) /* F7 */
119#define USART_CR2_MSBFIRST BIT(19) /* F7 */
120#define USART_CR2_ABREN BIT(20) /* F7 */
121#define USART_CR2_ABRMOD_MASK GENMASK(22, 21) /* F7 */
122#define USART_CR2_RTOEN BIT(23) /* F7 */
123#define USART_CR2_ADD_F7_MASK GENMASK(31, 24) /* F7 */
124
125/* USART_CR3 */
126#define USART_CR3_EIE BIT(0)
127#define USART_CR3_IREN BIT(1)
128#define USART_CR3_IRLP BIT(2)
129#define USART_CR3_HDSEL BIT(3)
130#define USART_CR3_NACK BIT(4)
131#define USART_CR3_SCEN BIT(5)
132#define USART_CR3_DMAR BIT(6)
133#define USART_CR3_DMAT BIT(7)
134#define USART_CR3_RTSE BIT(8)
135#define USART_CR3_CTSE BIT(9)
136#define USART_CR3_CTSIE BIT(10)
137#define USART_CR3_ONEBIT BIT(11)
138#define USART_CR3_OVRDIS BIT(12) /* F7 */
139#define USART_CR3_DDRE BIT(13) /* F7 */
140#define USART_CR3_DEM BIT(14) /* F7 */
141#define USART_CR3_DEP BIT(15) /* F7 */
142#define USART_CR3_SCARCNT_MASK GENMASK(19, 17) /* F7 */
143#define USART_CR3_WUS_MASK GENMASK(21, 20) /* H7 */
144#define USART_CR3_WUS_START_BIT BIT(21) /* H7 */
145#define USART_CR3_WUFIE BIT(22) /* H7 */
146#define USART_CR3_TXFTIE BIT(23) /* H7 */
147#define USART_CR3_TCBGTIE BIT(24) /* H7 */
148#define USART_CR3_RXFTCFG_MASK GENMASK(27, 25) /* H7 */
149#define USART_CR3_RXFTCFG_SHIFT 25 /* H7 */
150#define USART_CR3_RXFTIE BIT(28) /* H7 */
151#define USART_CR3_TXFTCFG_MASK GENMASK(31, 29) /* H7 */
152#define USART_CR3_TXFTCFG_SHIFT 29 /* H7 */
153
154/* USART_GTPR */
155#define USART_GTPR_PSC_MASK GENMASK(7, 0)
156#define USART_GTPR_GT_MASK GENMASK(15, 8)
157
158/* USART_RTOR */
159#define USART_RTOR_RTO_MASK GENMASK(23, 0) /* F7 */
160#define USART_RTOR_BLEN_MASK GENMASK(31, 24) /* F7 */
161
162/* USART_RQR */
163#define USART_RQR_ABRRQ BIT(0) /* F7 */
164#define USART_RQR_SBKRQ BIT(1) /* F7 */
165#define USART_RQR_MMRQ BIT(2) /* F7 */
166#define USART_RQR_RXFRQ BIT(3) /* F7 */
167#define USART_RQR_TXFRQ BIT(4) /* F7 */
168
169/* USART_ICR */
170#define USART_ICR_PECF BIT(0) /* F7 */
171#define USART_ICR_FECF BIT(1) /* F7 */
172#define USART_ICR_ORECF BIT(3) /* F7 */
173#define USART_ICR_IDLECF BIT(4) /* F7 */
174#define USART_ICR_TCCF BIT(6) /* F7 */
175#define USART_ICR_CTSCF BIT(9) /* F7 */
176#define USART_ICR_RTOCF BIT(11) /* F7 */
177#define USART_ICR_EOBCF BIT(12) /* F7 */
178#define USART_ICR_CMCF BIT(17) /* F7 */
179#define USART_ICR_WUCF BIT(20) /* H7 */
180
181/* USART_PRESC */
182#define USART_PRESC GENMASK(3, 0) /* H7 */
183#define USART_PRESC_MAX 0b1011
184
185/* USART_HWCFCR1 */
186#define USART_HWCFGR1_CFG8 GENMASK(31, 28) /* MP1 */
187
188#define STM32_SERIAL_NAME "ttySTM"
189#define STM32_MAX_PORTS 9
190#define STM32H7_USART_FIFO_SIZE 16
191
192#define RX_BUF_L 4096 /* dma rx buffer length */
193#define RX_BUF_P (RX_BUF_L / 2) /* dma rx buffer period */
194#define TX_BUF_L RX_BUF_L /* dma tx buffer length */
195
196#define STM32_USART_TIMEOUT_USEC USEC_PER_SEC /* 1s timeout in µs */
197
198struct stm32_port {
199 struct uart_port port;
200 struct clk *clk;
201 const struct stm32_usart_info *info;
202 struct dma_chan *rx_ch; /* dma rx channel */
203 dma_addr_t rx_dma_buf; /* dma rx buffer bus address */
204 unsigned char *rx_buf; /* dma rx buffer cpu address */
205 struct dma_chan *tx_ch; /* dma tx channel */
206 dma_addr_t tx_dma_buf; /* dma tx buffer bus address */
207 unsigned char *tx_buf; /* dma tx buffer cpu address */
208 u32 cr1_irq; /* USART_CR1_RXNEIE or RTOIE */
209 u32 cr3_irq; /* USART_CR3_RXFTIE */
210 int last_res;
211 bool tx_dma_busy; /* dma tx transaction in progress */
212 bool rx_dma_busy; /* dma rx transaction in progress */
213 bool throttled; /* port throttled */
214 bool hw_flow_control;
215 bool swap; /* swap RX & TX pins */
216 bool fifoen;
217 int rxftcfg; /* RX FIFO threshold CFG */
218 int txftcfg; /* TX FIFO threshold CFG */
219 bool wakeup_src;
220 int rdr_mask; /* receive data register mask */
221 struct mctrl_gpios *gpios; /* modem control gpios */
222 struct dma_tx_state rx_dma_state;
223};
224
225static struct stm32_port stm32_ports[STM32_MAX_PORTS];
226static struct uart_driver stm32_usart_driver;