1 /*
2  *  Copyright (C) 2013 Altera Corporation <www.altera.com>
3  *
4  * SPDX-License-Identifier:	GPL-2.0+
5  */
6 
7 #include <common.h>
8 #include <errno.h>
9 #include <asm/io.h>
10 #include <asm/arch/freeze_controller.h>
11 #include <asm/arch/scan_manager.h>
12 #include <asm/arch/system_manager.h>
13 
14 /*
15  * Maximum polling loop to wait for IO scan chain engine becomes idle
16  * to prevent infinite loop. It is important that this is NOT changed
17  * to delay using timer functions, since at the time this function is
18  * called, timer might not yet be inited.
19  */
20 #define SCANMGR_MAX_DELAY		100
21 
22 /*
23  * Maximum length of TDI_TDO packet payload is 128 bits,
24  * represented by (length - 1) in TDI_TDO header.
25  */
26 #define TDI_TDO_MAX_PAYLOAD		127
27 
28 #define SCANMGR_STAT_ACTIVE		(1 << 31)
29 #define SCANMGR_STAT_WFIFOCNT_MASK	0x70000000
30 
31 DECLARE_GLOBAL_DATA_PTR;
32 
33 static const struct socfpga_scan_manager *scan_manager_base =
34 		(void *)(SOCFPGA_SCANMGR_ADDRESS);
35 static const struct socfpga_freeze_controller *freeze_controller_base =
36 		(void *)(SOCFPGA_SYSMGR_ADDRESS + SYSMGR_FRZCTRL_ADDRESS);
37 static struct socfpga_system_manager *sys_mgr_base =
38 	(struct socfpga_system_manager *)SOCFPGA_SYSMGR_ADDRESS;
39 
40 /**
41  * scan_chain_engine_is_idle() - Check if the JTAG scan chain is idle
42  * @max_iter:	Maximum number of iterations to wait for idle
43  *
44  * Function to check IO scan chain engine status and wait if the engine is
45  * is active. Poll the IO scan chain engine till maximum iteration reached.
46  */
47 static u32 scan_chain_engine_is_idle(u32 max_iter)
48 {
49 	const u32 mask = SCANMGR_STAT_ACTIVE | SCANMGR_STAT_WFIFOCNT_MASK;
50 	u32 status;
51 
52 	/* Poll the engine until the scan engine is inactive. */
53 	do {
54 		status = readl(&scan_manager_base->stat);
55 		if (!(status & mask))
56 			return 0;
57 	} while (max_iter--);
58 
59 	return -ETIMEDOUT;
60 }
61 
62 #define JTAG_BP_INSN		(1 << 0)
63 #define JTAG_BP_TMS		(1 << 1)
64 #define JTAG_BP_PAYLOAD		(1 << 2)
65 #define JTAG_BP_2BYTE		(1 << 3)
66 #define JTAG_BP_4BYTE		(1 << 4)
67 
68 /**
69  * scan_mgr_jtag_io() - Access the JTAG chain
70  * @flags:	Control flags, used to configure the action on the JTAG
71  * @iarg:	Instruction argument
72  * @parg:	Payload argument or data
73  *
74  * Perform I/O on the JTAG chain
75  */
76 static void scan_mgr_jtag_io(const u32 flags, const u8 iarg, const u32 parg)
77 {
78 	u32 data = parg;
79 
80 	if (flags & JTAG_BP_INSN) {	/* JTAG instruction */
81 		/*
82 		 * The SCC JTAG register is LSB first, so make
83 		 * space for the instruction at the LSB.
84 		 */
85 		data <<= 8;
86 		if (flags & JTAG_BP_TMS) {
87 			data |= (0 << 7);	/* TMS instruction. */
88 			data |= iarg & 0x3f;	/* TMS arg is 6 bits. */
89 			if (flags & JTAG_BP_PAYLOAD)
90 				data |= (1 << 6);
91 		} else {
92 			data |= (1 << 7);	/* TDI/TDO instruction. */
93 			data |= iarg & 0xf;	/* TDI/TDO arg is 4 bits. */
94 			if (flags & JTAG_BP_PAYLOAD)
95 				data |= (1 << 4);
96 		}
97 	}
98 
99 	if (flags & JTAG_BP_4BYTE)
100 		writel(data, &scan_manager_base->fifo_quad_byte);
101 	else if (flags & JTAG_BP_2BYTE)
102 		writel(data & 0xffff, &scan_manager_base->fifo_double_byte);
103 	else
104 		writel(data & 0xff, &scan_manager_base->fifo_single_byte);
105 }
106 
107 /**
108  * scan_mgr_jtag_insn_data() - Send JTAG instruction and data
109  * @iarg:	Instruction argument
110  * @data:	Associated data
111  * @dlen:	Length of data in bits
112  *
113  * This function is used when programming the IO chains to submit the
114  * instruction followed by variable length payload.
115  */
116 static int
117 scan_mgr_jtag_insn_data(const u8 iarg, const unsigned long *data,
118 			const unsigned int dlen)
119 {
120 	int i, j;
121 
122 	scan_mgr_jtag_io(JTAG_BP_INSN | JTAG_BP_2BYTE, iarg, dlen - 1);
123 
124 	/* 32 bits or more remain */
125 	for (i = 0; i < dlen / 32; i++)
126 		scan_mgr_jtag_io(JTAG_BP_4BYTE, 0x0, data[i]);
127 
128 	if ((dlen % 32) > 24) {	/* 31...24 bits remain */
129 		scan_mgr_jtag_io(JTAG_BP_4BYTE, 0x0, data[i]);
130 	} else if (dlen % 32) {	/* 24...1 bit remain */
131 		for (j = 0; j < dlen % 32; j += 8)
132 			scan_mgr_jtag_io(0, 0x0, data[i] >> j);
133 	}
134 
135 	return scan_chain_engine_is_idle(SCANMGR_MAX_DELAY);
136 }
137 
138 /**
139  * scan_mgr_io_scan_chain_prg() - Program HPS IO Scan Chain
140  * @io_scan_chain_id:		IO scan chain ID
141  */
142 static int scan_mgr_io_scan_chain_prg(const unsigned int io_scan_chain_id)
143 {
144 	u32 io_scan_chain_len_in_bits;
145 	const unsigned long *iocsr_scan_chain;
146 	unsigned int rem, idx = 0;
147 	int ret;
148 
149 	ret = iocsr_get_config_table(io_scan_chain_id, &iocsr_scan_chain,
150 				     &io_scan_chain_len_in_bits);
151 	if (ret)
152 		return 1;
153 
154 	/*
155 	 * De-assert reinit if the IO scan chain is intended for HIO. In
156 	 * this, its the chain 3.
157 	 */
158 	if (io_scan_chain_id == 3)
159 		clrbits_le32(&freeze_controller_base->hioctrl,
160 			     SYSMGR_FRZCTRL_HIOCTRL_DLLRST_MASK);
161 
162 	/*
163 	 * Check if the scan chain engine is inactive and the
164 	 * WFIFO is empty before enabling the IO scan chain
165 	 */
166 	ret = scan_chain_engine_is_idle(SCANMGR_MAX_DELAY);
167 	if (ret)
168 		return ret;
169 
170 	/*
171 	 * Enable IO Scan chain based on scan chain id
172 	 * Note: only one chain can be enabled at a time
173 	 */
174 	setbits_le32(&scan_manager_base->en, 1 << io_scan_chain_id);
175 
176 	/* Program IO scan chain. */
177 	while (io_scan_chain_len_in_bits) {
178 		if (io_scan_chain_len_in_bits > 128)
179 			rem = 128;
180 		else
181 			rem = io_scan_chain_len_in_bits;
182 
183 		ret = scan_mgr_jtag_insn_data(0x0, &iocsr_scan_chain[idx], rem);
184 		if (ret)
185 			goto error;
186 		io_scan_chain_len_in_bits -= rem;
187 		idx += 4;
188 	}
189 
190 	/* Disable IO Scan chain when configuration done*/
191 	clrbits_le32(&scan_manager_base->en, 1 << io_scan_chain_id);
192 	return 0;
193 
194 error:
195 	/* Disable IO Scan chain when error detected */
196 	clrbits_le32(&scan_manager_base->en, 1 << io_scan_chain_id);
197 	return ret;
198 }
199 
200 int scan_mgr_configure_iocsr(void)
201 {
202 	int status = 0;
203 
204 	/* configure the IOCSR through scan chain */
205 	status |= scan_mgr_io_scan_chain_prg(0);
206 	status |= scan_mgr_io_scan_chain_prg(1);
207 	status |= scan_mgr_io_scan_chain_prg(2);
208 	status |= scan_mgr_io_scan_chain_prg(3);
209 	return status;
210 }
211 
212 /**
213  * scan_mgr_get_fpga_id() - Obtain FPGA JTAG ID
214  *
215  * This function obtains JTAG ID from the FPGA TAP controller.
216  */
217 u32 scan_mgr_get_fpga_id(void)
218 {
219 	const unsigned long data = 0;
220 	u32 id = 0xffffffff;
221 	int ret;
222 
223 	/* Enable HPS to talk to JTAG in the FPGA through the System Manager */
224 	writel(0x1, &sys_mgr_base->scanmgrgrp_ctrl);
225 
226 	/* Enable port 7 */
227 	writel(0x80, &scan_manager_base->en);
228 	/* write to CSW to make s2f_ntrst reset */
229 	writel(0x02, &scan_manager_base->stat);
230 
231 	/* Add a pause */
232 	mdelay(1);
233 
234 	/* write 0x00 to CSW to clear the s2f_ntrst */
235 	writel(0, &scan_manager_base->stat);
236 
237 	/*
238 	 * Go to Test-Logic-Reset state.
239 	 * This sets TAP controller into IDCODE mode.
240 	 */
241 	scan_mgr_jtag_io(JTAG_BP_INSN | JTAG_BP_TMS, 0x1f | (1 << 5), 0x0);
242 
243 	/* Go to Run-Test/Idle -> DR-Scan -> Capture-DR -> Shift-DR state. */
244 	scan_mgr_jtag_io(JTAG_BP_INSN | JTAG_BP_TMS, 0x02 | (1 << 4), 0x0);
245 
246 	/*
247 	 * Push 4 bytes of data through TDI->DR->TDO.
248 	 *
249 	 * Length of TDI data is 32bits (length - 1) and they are only
250 	 * zeroes as we care only for TDO data.
251 	 */
252 	ret = scan_mgr_jtag_insn_data(0x4, &data, 32);
253 	/* Read 32 bit from captured JTAG data. */
254 	if (!ret)
255 		id = readl(&scan_manager_base->fifo_quad_byte);
256 
257 	/* Disable all port */
258 	writel(0, &scan_manager_base->en);
259 	writel(0, &sys_mgr_base->scanmgrgrp_ctrl);
260 
261 	return id;
262 }
263