xref: /openbmc/u-boot/arch/arm/mach-socfpga/scan_manager.c (revision 963bca63b6c13f72bc164690b0f5de08c9787384)
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 <asm/io.h>
9 #include <asm/arch/freeze_controller.h>
10 #include <asm/arch/scan_manager.h>
11 
12 DECLARE_GLOBAL_DATA_PTR;
13 
14 static const struct socfpga_scan_manager *scan_manager_base =
15 		(void *)(SOCFPGA_SCANMGR_ADDRESS);
16 static const struct socfpga_freeze_controller *freeze_controller_base =
17 		(void *)(SOCFPGA_SYSMGR_ADDRESS + SYSMGR_FRZCTRL_ADDRESS);
18 
19 /*
20  * Function to check IO scan chain engine status and wait if the engine is
21  * is active. Poll the IO scan chain engine till maximum iteration reached.
22  */
23 static inline uint32_t scan_chain_engine_is_idle(uint32_t max_iter)
24 {
25 	uint32_t scanmgr_status;
26 
27 	scanmgr_status = readl(&scan_manager_base->stat);
28 
29 	/* Poll the engine until the scan engine is inactive */
30 	while (SCANMGR_STAT_ACTIVE_GET(scanmgr_status) ||
31 	      (SCANMGR_STAT_WFIFOCNT_GET(scanmgr_status) > 0)) {
32 		max_iter--;
33 		if (max_iter > 0)
34 			scanmgr_status = readl(&scan_manager_base->stat);
35 		else
36 			return 0;
37 	}
38 	return 1;
39 }
40 
41 /**
42  * scan_mgr_io_scan_chain_prg() - Program HPS IO Scan Chain
43  * @io_scan_chain_id:		IO scan chain ID
44  */
45 static int scan_mgr_io_scan_chain_prg(const unsigned int io_scan_chain_id)
46 {
47 	uint16_t tdi_tdo_header;
48 	uint32_t io_program_iter;
49 	uint32_t io_scan_chain_data_residual;
50 	uint32_t residual;
51 	uint32_t i, ret;
52 	uint32_t index = 0;
53 	uint32_t io_scan_chain_len_in_bits;
54 	const unsigned long *iocsr_scan_chain;
55 
56 	ret = iocsr_get_config_table(io_scan_chain_id, &iocsr_scan_chain,
57 				     &io_scan_chain_len_in_bits);
58 	if (ret)
59 		return 1;
60 
61 	/*
62 	 * De-assert reinit if the IO scan chain is intended for HIO. In
63 	 * this, its the chain 3.
64 	 */
65 	if (io_scan_chain_id == 3)
66 		clrbits_le32(&freeze_controller_base->hioctrl,
67 			     SYSMGR_FRZCTRL_HIOCTRL_DLLRST_MASK);
68 
69 	/*
70 	 * Check if the scan chain engine is inactive and the
71 	 * WFIFO is empty before enabling the IO scan chain
72 	 */
73 	if (!scan_chain_engine_is_idle(SCAN_MAX_DELAY))
74 		return 1;
75 
76 	/*
77 	 * Enable IO Scan chain based on scan chain id
78 	 * Note: only one chain can be enabled at a time
79 	 */
80 	setbits_le32(&scan_manager_base->en, 1 << io_scan_chain_id);
81 
82 	/*
83 	 * Calculate number of iteration needed for full 128-bit (4 x32-bits)
84 	 * bits shifting. Each TDI_TDO packet can shift in maximum 128-bits
85 	 */
86 	io_program_iter	= io_scan_chain_len_in_bits >>
87 		IO_SCAN_CHAIN_128BIT_SHIFT;
88 	io_scan_chain_data_residual = io_scan_chain_len_in_bits &
89 		IO_SCAN_CHAIN_128BIT_MASK;
90 
91 	/* Construct TDI_TDO packet for 128-bit IO scan chain (2 bytes) */
92 	tdi_tdo_header = TDI_TDO_HEADER_FIRST_BYTE |
93 		(TDI_TDO_MAX_PAYLOAD <<	TDI_TDO_HEADER_SECOND_BYTE_SHIFT);
94 
95 	/* Program IO scan chain in 128-bit iteration */
96 	for (i = 0; i < io_program_iter; i++) {
97 		/* write TDI_TDO packet header to scan manager */
98 		writel(tdi_tdo_header,	&scan_manager_base->fifo_double_byte);
99 
100 		/* calculate array index. Multiply by 4 as write 4 x 32bits */
101 		index = i * 4;
102 
103 		/* write 4 successive 32-bit IO scan chain data into WFIFO */
104 		writel(iocsr_scan_chain[index],
105 		       &scan_manager_base->fifo_quad_byte);
106 		writel(iocsr_scan_chain[index + 1],
107 		       &scan_manager_base->fifo_quad_byte);
108 		writel(iocsr_scan_chain[index + 2],
109 		       &scan_manager_base->fifo_quad_byte);
110 		writel(iocsr_scan_chain[index + 3],
111 		       &scan_manager_base->fifo_quad_byte);
112 
113 		/*
114 		 * Check if the scan chain engine has completed the
115 		 * IO scan chain data shifting
116 		 */
117 		if (!scan_chain_engine_is_idle(SCAN_MAX_DELAY))
118 			goto error;
119 	}
120 
121 	/* Calculate array index for final TDI_TDO packet */
122 	index = io_program_iter * 4;
123 
124 	/* Final TDI_TDO packet if any */
125 	if (io_scan_chain_data_residual) {
126 		/*
127 		 * Calculate number of quad bytes FIFO write
128 		 * needed for the final TDI_TDO packet
129 		 */
130 		io_program_iter	= io_scan_chain_data_residual >>
131 			IO_SCAN_CHAIN_32BIT_SHIFT;
132 
133 		/*
134 		 * Construct TDI_TDO packet for remaining IO
135 		 * scan chain (2 bytes)
136 		 */
137 		tdi_tdo_header	= TDI_TDO_HEADER_FIRST_BYTE |
138 			((io_scan_chain_data_residual - 1) <<
139 			TDI_TDO_HEADER_SECOND_BYTE_SHIFT);
140 
141 		/*
142 		 * Program the last part of IO scan chain write TDI_TDO packet
143 		 * header (2 bytes) to scan manager
144 		 */
145 		writel(tdi_tdo_header, &scan_manager_base->fifo_double_byte);
146 
147 		for (i = 0; i < io_program_iter; i++) {
148 			/*
149 			 * write remaining scan chain data into scan
150 			 * manager WFIFO with 4 bytes write
151 			*/
152 			writel(iocsr_scan_chain[index + i],
153 			       &scan_manager_base->fifo_quad_byte);
154 		}
155 
156 		index += io_program_iter;
157 		residual = io_scan_chain_data_residual &
158 			IO_SCAN_CHAIN_32BIT_MASK;
159 
160 		if (IO_SCAN_CHAIN_PAYLOAD_24BIT < residual) {
161 			/*
162 			 * write the last 4B scan chain data
163 			 * into scan manager WFIFO
164 			 */
165 			writel(iocsr_scan_chain[index],
166 			       &scan_manager_base->fifo_quad_byte);
167 		} else {
168 			/*
169 			 * write the remaining 1 - 3 bytes scan chain
170 			 * data into scan manager WFIFO byte by byte
171 			 * to prevent JTAG engine shifting unused data
172 			 * from the FIFO and mistaken the data as a
173 			 * valid command (even though unused bits are
174 			 * set to 0, but just to prevent hardware
175 			 * glitch)
176 			 */
177 			for (i = 0; i < residual; i += 8) {
178 				writel(((iocsr_scan_chain[index] >> i)
179 					& IO_SCAN_CHAIN_BYTE_MASK),
180 					&scan_manager_base->fifo_single_byte);
181 			}
182 		}
183 
184 		/*
185 		 * Check if the scan chain engine has completed the
186 		 * IO scan chain data shifting
187 		 */
188 		if (!scan_chain_engine_is_idle(SCAN_MAX_DELAY))
189 			goto error;
190 	}
191 
192 	/* Disable IO Scan chain when configuration done*/
193 	clrbits_le32(&scan_manager_base->en, 1 << io_scan_chain_id);
194 	return 0;
195 
196 error:
197 	/* Disable IO Scan chain when error detected */
198 	clrbits_le32(&scan_manager_base->en, 1 << io_scan_chain_id);
199 	return 1;
200 }
201 
202 int scan_mgr_configure_iocsr(void)
203 {
204 	int status = 0;
205 
206 	/* configure the IOCSR through scan chain */
207 	status |= scan_mgr_io_scan_chain_prg(0);
208 	status |= scan_mgr_io_scan_chain_prg(1);
209 	status |= scan_mgr_io_scan_chain_prg(2);
210 	status |= scan_mgr_io_scan_chain_prg(3);
211 	return status;
212 }
213