1 // SPDX-License-Identifier: BSD-2-Clause
2 /*
3  * Cadence DDR Controller
4  *
5  * Copyright (C) 2015 Renesas Electronics Europe Ltd
6  */
7 
8 /*
9  * The Cadence DDR Controller has a huge number of registers that principally
10  * cover two aspects, DDR specific timing information and AXI bus interfacing.
11  * Cadence's TCL script generates all of the register values for specific
12  * DDR devices operating at a specific frequency. The TCL script uses Denali
13  * SOMA files as inputs. The tool also generates the AXI bus register values as
14  * well, however this driver assumes that users will want to modifiy these to
15  * meet a specific application's needs.
16  * Therefore, this driver is passed two arrays containing register values for
17  * the DDR device specific information, and explicity sets the AXI registers.
18  *
19  * AXI bus interfacing:
20  *  The controller has four AXI slaves connections, and each of these can be
21  * programmed to accept requests from specific AXI masters (using their IDs).
22  * The regions of DDR that can be accessed by each AXI slave can be set such
23  * as to isolate DDR used by one AXI master from another. Further, the maximum
24  * bandwidth allocated to each AXI slave can be set.
25  */
26 
27 #include <linux/delay.h>
28 #include <linux/sizes.h>
29 #include <asm/io.h>
30 #include <wait_bit.h>
31 #include <renesas/ddr_ctrl.h>
32 
33 /* avoid warning for real pr_debug in <linux/printk.h> */
34 #ifdef pr_debug
35 #undef pr_debug
36 #endif
37 
38 #ifdef DEBUG
39 	#define pr_debug(fmt, args...)	printf(fmt, ##args)
40 	#define pr_debug2(fmt, args...)	printf(fmt, ##args)
41 #else
42 	#define pr_debug(fmt, args...)
43 	#define pr_debug2(fmt, args...)
44 #endif
45 
46 #define DDR_NR_AXI_PORTS		4
47 #define DDR_NR_ENTRIES			16
48 
49 #define DDR_START_REG			(0)		/* DENALI_CTL_00 */
50 #define DDR_CS0_MR1_REG			(32 * 4)	/* DENALI_CTL_32 */
51 #define DDR_CS0_MR2_REG			(32 * 4 + 2)	/* DENALI_CTL_32 */
52 #define DDR_CS1_MR1_REG			(34 * 4 + 2)	/* DENALI_CTL_34 */
53 #define DDR_CS1_MR2_REG			(35 * 4)	/* DENALI_CTL_35 */
54 #define DDR_ECC_ENABLE_REG		(36 * 4 + 2)	/* DENALI_CTL_36 */
55 #define DDR_ECC_DISABLE_W_UC_ERR_REG	(37 * 4 + 2)	/* DENALI_CTL_37 */
56 #define DDR_HALF_DATAPATH_REG		(54 * 4)	/* DENALI_CTL_54 */
57 #define DDR_INTERRUPT_STATUS		(56 * 4)	/* DENALI_CTL_56 */
58 #define DDR_INTERRUPT_ACK		(57 * 4)	/* DENALI_CTL_57 */
59 #define DDR_INTERRUPT_MASK		(58 * 4)	/* DENALI_CTL_58 */
60 #define DDR_CS0_ODT_MAP_REG		(62 * 4 + 2)	/* DENALI_CTL_62 */
61 #define DDR_CS1_ODT_MAP_REG		(63 * 4)	/* DENALI_CTL_63 */
62 #define DDR_ODT_TODTL_2CMD		(63 * 4 + 2)	/* DENALI_CTL_63 */
63 #define DDR_ODT_TODTH_WR		(63 * 4 + 3)	/* DENALI_CTL_63 */
64 #define DDR_ODT_TODTH_RD		(64 * 4 + 0)	/* DENALI_CTL_64 */
65 #define DDR_ODT_EN			(64 * 4 + 1)	/* DENALI_CTL_64 */
66 #define DDR_ODT_WR_TO_ODTH		(64 * 4 + 2)	/* DENALI_CTL_64 */
67 #define DDR_ODT_RD_TO_ODTH		(64 * 4 + 3)	/* DENALI_CTL_64 */
68 #define DDR_DIFF_CS_DELAY_REG		(66 * 4)	/* DENALI_CTL_66 */
69 #define DDR_SAME_CS_DELAY_REG		(67 * 4)	/* DENALI_CTL_67 */
70 #define DDR_RW_PRIORITY_REGS		(87 * 4 + 2)	/* DENALI_CTL_87 */
71 #define DDR_RW_FIFO_TYPE_REGS		(88 * 4)	/* DENALI_CTL_88 */
72 #define DDR_AXI_PORT_PROT_ENABLE_REG	(90 * 4 + 3)	/* DENALI_CTL_90 */
73 #define DDR_ADDR_RANGE_REGS		(91 * 4)	/* DENALI_CTL_91 */
74 #define DDR_RANGE_PROT_REGS		(218 * 4 + 2)	/* DENALI_CTL_218 */
75 #define DDR_ARB_CMD_Q_THRESHOLD_REG	(346 * 4 + 2)	/* DENALI_CTL_346 */
76 #define DDR_AXI_PORT_BANDWIDTH_REG	(346 * 4 + 3)	/* DENALI_CTL_346 */
77 #define DDR_OPT_RMODW_REG		(372 * 4 + 3)	/* DENALI_CTL_372 */
78 
ddrc_writeb(u8 val,void * p)79 static void ddrc_writeb(u8 val, void *p)
80 {
81 	pr_debug2("DDR: %p = 0x%02x\n", p, val);
82 	writeb(val, p);
83 }
84 
ddrc_writew(u16 val,void * p)85 static void ddrc_writew(u16 val, void *p)
86 {
87 	pr_debug2("DDR: %p = 0x%04x\n", p, val);
88 	writew(val, p);
89 }
90 
ddrc_writel(u32 val,void * p)91 static void ddrc_writel(u32 val, void *p)
92 {
93 	pr_debug2("DDR: %p = 0x%08x\n", p, val);
94 	writel(val, p);
95 }
96 
cdns_ddr_set_mr1(void * base,int cs,u16 odt_impedance,u16 drive_strength)97 void cdns_ddr_set_mr1(void *base, int cs, u16 odt_impedance, u16 drive_strength)
98 {
99 	void *reg;
100 	u16 tmp;
101 
102 	if (cs == 0)
103 		reg = (u8 *)base + DDR_CS0_MR1_REG;
104 	else
105 		reg = (u8 *)base + DDR_CS1_MR1_REG;
106 
107 	tmp = readw(reg);
108 
109 	tmp &= ~MODE_REGISTER_MASK;
110 	tmp |=  MODE_REGISTER_MR1;
111 
112 	tmp &= ~MR1_ODT_IMPEDANCE_MASK;
113 	tmp |=  odt_impedance;
114 
115 	tmp &= ~MR1_DRIVE_STRENGTH_MASK;
116 	tmp |=  drive_strength;
117 
118 	writew(tmp, reg);
119 }
120 
cdns_ddr_set_mr2(void * base,int cs,u16 dynamic_odt,u16 self_refresh_temp)121 void cdns_ddr_set_mr2(void *base, int cs, u16 dynamic_odt, u16 self_refresh_temp)
122 {
123 	void *reg;
124 	u16 tmp;
125 
126 	if (cs == 0)
127 		reg = (u8 *)base + DDR_CS0_MR2_REG;
128 	else
129 		reg = (u8 *)base + DDR_CS1_MR2_REG;
130 
131 	tmp = readw(reg);
132 
133 	tmp &= ~MODE_REGISTER_MASK;
134 	tmp |=  MODE_REGISTER_MR2;
135 
136 	tmp &= ~MR2_DYNAMIC_ODT_MASK;
137 	tmp |=  dynamic_odt;
138 
139 	tmp &= ~MR2_SELF_REFRESH_TEMP_MASK;
140 	tmp |=  self_refresh_temp;
141 
142 	writew(tmp, reg);
143 }
144 
cdns_ddr_set_odt_map(void * base,int cs,u16 odt_map)145 void cdns_ddr_set_odt_map(void *base, int cs, u16 odt_map)
146 {
147 	void *reg;
148 
149 	if (cs == 0)
150 		reg = (u8 *)base + DDR_CS0_ODT_MAP_REG;
151 	else
152 		reg = (u8 *)base + DDR_CS1_ODT_MAP_REG;
153 
154 	writew(odt_map, reg);
155 }
156 
cdns_ddr_set_odt_times(void * base,u8 TODTL_2CMD,u8 TODTH_WR,u8 TODTH_RD,u8 WR_TO_ODTH,u8 RD_TO_ODTH)157 void cdns_ddr_set_odt_times(void *base, u8 TODTL_2CMD, u8 TODTH_WR, u8 TODTH_RD,
158 			    u8 WR_TO_ODTH, u8 RD_TO_ODTH)
159 {
160 	writeb(TODTL_2CMD,	(u8 *)base + DDR_ODT_TODTL_2CMD);
161 	writeb(TODTH_WR,	(u8 *)base + DDR_ODT_TODTH_WR);
162 	writeb(TODTH_RD,	(u8 *)base + DDR_ODT_TODTH_RD);
163 	writeb(1,		(u8 *)base + DDR_ODT_EN);
164 	writeb(WR_TO_ODTH,	(u8 *)base + DDR_ODT_WR_TO_ODTH);
165 	writeb(RD_TO_ODTH,	(u8 *)base + DDR_ODT_RD_TO_ODTH);
166 }
167 
cdns_ddr_set_same_cs_delays(void * base,u8 r2r,u8 r2w,u8 w2r,u8 w2w)168 void cdns_ddr_set_same_cs_delays(void *base, u8 r2r, u8 r2w, u8 w2r, u8 w2w)
169 {
170 	u32 val = (w2w << 24) | (w2r << 16) | (r2w << 8) | r2r;
171 
172 	writel(val, (u8 *)base + DDR_SAME_CS_DELAY_REG);
173 }
174 
cdns_ddr_set_diff_cs_delays(void * base,u8 r2r,u8 r2w,u8 w2r,u8 w2w)175 void cdns_ddr_set_diff_cs_delays(void *base, u8 r2r, u8 r2w, u8 w2r, u8 w2w)
176 {
177 	u32 val = (w2w << 24) | (w2r << 16) | (r2w << 8) | r2r;
178 
179 	writel(val, (u8 *)base + DDR_DIFF_CS_DELAY_REG);
180 }
181 
cdns_ddr_set_port_rw_priority(void * base,int port,u8 read_pri,u8 write_pri)182 void cdns_ddr_set_port_rw_priority(void *base, int port,
183 				   u8 read_pri, u8 write_pri)
184 {
185 	u8 *reg8 = (u8 *)base + DDR_RW_PRIORITY_REGS;
186 
187 	reg8 += (port * 3);
188 	pr_debug("%s port %d (reg8=%p, DENALI_CTL_%d)\n",
189 		 __func__, port, reg8, (reg8 - (u8 *)base) / 4);
190 
191 	ddrc_writeb(read_pri, reg8++);
192 	ddrc_writeb(write_pri, reg8++);
193 }
194 
195 /* The DDR Controller has 16 entries. Each entry can specify an allowed address
196  * range (with 16KB resolution) for one of the 4 AXI slave ports.
197  */
cdns_ddr_enable_port_addr_range(void * base,int port,int entry,u32 addr_start,u32 size)198 void cdns_ddr_enable_port_addr_range(void *base, int port, int entry,
199 				     u32 addr_start, u32 size)
200 {
201 	u32 addr_end;
202 	u32 *reg32 = (u32 *)((u8 *)base + DDR_ADDR_RANGE_REGS);
203 	u32 tmp;
204 
205 	reg32 += (port * DDR_NR_ENTRIES * 2);
206 	reg32 += (entry * 2);
207 	pr_debug("%s port %d, entry %d (reg32=%p, DENALI_CTL_%d)\n",
208 		 __func__, port, entry, reg32, ((u8 *)reg32 - (u8 *)base) / 4);
209 
210 	/* These registers represent 16KB address blocks */
211 	addr_start /= SZ_16K;
212 	size /= SZ_16K;
213 	if (size)
214 		addr_end = addr_start + size - 1;
215 	else
216 		addr_end = addr_start;
217 
218 	ddrc_writel(addr_start, reg32++);
219 
220 	/*
221 	 * end_addr: Ensure we only set the bottom 18-bits as DENALI_CTL_218
222 	 * also contains the AXI0 range protection bits.
223 	 */
224 	tmp = readl(reg32);
225 	tmp &= ~(BIT(18) - 1);
226 	tmp |= addr_end;
227 	ddrc_writel(tmp, reg32);
228 }
229 
cdns_ddr_enable_addr_range(void * base,int entry,u32 addr_start,u32 size)230 void cdns_ddr_enable_addr_range(void *base, int entry,
231 				u32 addr_start, u32 size)
232 {
233 	int axi;
234 
235 	for (axi = 0; axi < DDR_NR_AXI_PORTS; axi++)
236 		cdns_ddr_enable_port_addr_range(base, axi, entry,
237 						addr_start, size);
238 }
239 
cdns_ddr_enable_port_prot(void * base,int port,int entry,enum cdns_ddr_range_prot range_protection_bits,u16 range_RID_check_bits,u16 range_WID_check_bits,u8 range_RID_check_bits_ID_lookup,u8 range_WID_check_bits_ID_lookup)240 void cdns_ddr_enable_port_prot(void *base, int port, int entry,
241 			       enum cdns_ddr_range_prot range_protection_bits,
242 			       u16 range_RID_check_bits,
243 			       u16 range_WID_check_bits,
244 			       u8 range_RID_check_bits_ID_lookup,
245 			       u8 range_WID_check_bits_ID_lookup)
246 {
247 	/*
248 	 * Technically, the offset here points to the byte before the start of
249 	 * the range protection registers. However, all entries consist of 8
250 	 * bytes, except the first one (which is missing a padding byte) so we
251 	 * work around that subtlely.
252 	 */
253 	u8 *reg8 = (u8 *)base + DDR_RANGE_PROT_REGS;
254 
255 	reg8 += (port * DDR_NR_ENTRIES * 8);
256 	reg8 += (entry * 8);
257 	pr_debug("%s port %d, entry %d (reg8=%p, DENALI_CTL_%d)\n",
258 		 __func__, port, entry, reg8, (reg8 - (u8 *)base) / 4);
259 
260 	if (port == 0 && entry == 0)
261 		ddrc_writeb(range_protection_bits, reg8 + 1);
262 	else
263 		ddrc_writeb(range_protection_bits, reg8);
264 
265 	ddrc_writew(range_RID_check_bits, reg8 + 2);
266 	ddrc_writew(range_WID_check_bits, reg8 + 4);
267 	ddrc_writeb(range_RID_check_bits_ID_lookup, reg8 + 6);
268 	ddrc_writeb(range_WID_check_bits_ID_lookup, reg8 + 7);
269 }
270 
cdns_ddr_enable_prot(void * base,int entry,enum cdns_ddr_range_prot range_protection_bits,u16 range_RID_check_bits,u16 range_WID_check_bits,u8 range_RID_check_bits_ID_lookup,u8 range_WID_check_bits_ID_lookup)271 void cdns_ddr_enable_prot(void *base, int entry,
272 			  enum cdns_ddr_range_prot range_protection_bits,
273 			  u16 range_RID_check_bits,
274 			  u16 range_WID_check_bits,
275 			  u8 range_RID_check_bits_ID_lookup,
276 			  u8 range_WID_check_bits_ID_lookup)
277 {
278 	int axi;
279 
280 	for (axi = 0; axi < DDR_NR_AXI_PORTS; axi++)
281 		cdns_ddr_enable_port_prot(base, axi, entry,
282 					  range_protection_bits,
283 					  range_RID_check_bits,
284 					  range_WID_check_bits,
285 					  range_RID_check_bits_ID_lookup,
286 					  range_WID_check_bits_ID_lookup);
287 }
288 
cdns_ddr_set_port_bandwidth(void * base,int port,u8 max_percent,u8 overflow_ok)289 void cdns_ddr_set_port_bandwidth(void *base, int port,
290 				 u8 max_percent, u8 overflow_ok)
291 {
292 	u8 *reg8 = (u8 *)base + DDR_AXI_PORT_BANDWIDTH_REG;
293 
294 	reg8 += (port * 3);
295 	pr_debug("%s port %d, (reg8=%p, DENALI_CTL_%d)\n",
296 		 __func__, port, reg8, (reg8 - (u8 *)base) / 4);
297 
298 	ddrc_writeb(max_percent, reg8++);	/* Maximum bandwidth percentage */
299 	ddrc_writeb(overflow_ok, reg8++);	/* Bandwidth overflow allowed */
300 }
301 
cdns_ddr_ctrl_init(void * ddr_ctrl_basex,int async,const u32 * reg0,const u32 * reg350,u32 ddr_start_addr,u32 ddr_size,int enable_ecc,int enable_8bit)302 void cdns_ddr_ctrl_init(void *ddr_ctrl_basex, int async,
303 			const u32 *reg0, const u32 *reg350,
304 			u32 ddr_start_addr, u32 ddr_size,
305 			int enable_ecc, int enable_8bit)
306 {
307 	int i, axi, entry;
308 	u32 *ddr_ctrl_base = (u32 *)ddr_ctrl_basex;
309 	u8 *base8 = (u8 *)ddr_ctrl_basex;
310 
311 	ddrc_writel(*reg0, ddr_ctrl_base + 0);
312 	/* 1 to 6 are read only */
313 	for (i = 7; i <= 26; i++)
314 		ddrc_writel(*(reg0 + i), ddr_ctrl_base + i);
315 	/* 27 to 29 are not changed */
316 	for (i = 30; i <= 87; i++)
317 		ddrc_writel(*(reg0 + i), ddr_ctrl_base + i);
318 
319 	/* Enable/disable ECC */
320 	if (enable_ecc) {
321 		pr_debug("%s enabling ECC\n", __func__);
322 		ddrc_writeb(1, base8 + DDR_ECC_ENABLE_REG);
323 	} else {
324 		ddrc_writeb(0, base8 + DDR_ECC_ENABLE_REG);
325 	}
326 
327 	/* ECC: Disable corruption for read/modify/write operations */
328 	ddrc_writeb(1, base8 + DDR_ECC_DISABLE_W_UC_ERR_REG);
329 
330 	/* Set 8/16-bit data width using reduce bit (enable half datapath)*/
331 	if (enable_8bit) {
332 		pr_debug("%s using 8-bit data\n", __func__);
333 		ddrc_writeb(1, base8 + DDR_HALF_DATAPATH_REG);
334 	} else {
335 		ddrc_writeb(0, base8 + DDR_HALF_DATAPATH_REG);
336 	}
337 
338 	/* Threshold for command queue */
339 	ddrc_writeb(4, base8 + DDR_ARB_CMD_Q_THRESHOLD_REG);
340 
341 	/* AXI port protection => enable */
342 	ddrc_writeb(0x01, base8 + DDR_AXI_PORT_PROT_ENABLE_REG);
343 
344 	/* Set port interface type, default port priority and bandwidths */
345 	for (axi = 0; axi < DDR_NR_AXI_PORTS; axi++) {
346 		/* port interface type: synchronous or asynchronous AXI clock */
347 		u8 *fifo_reg = base8 + DDR_RW_FIFO_TYPE_REGS + (axi * 3);
348 
349 		if (async)
350 			ddrc_writeb(0, fifo_reg);
351 		else
352 			ddrc_writeb(3, fifo_reg);
353 
354 		/* R/W priorities */
355 		cdns_ddr_set_port_rw_priority(ddr_ctrl_base, axi, 2, 2);
356 
357 		/* AXI bandwidth */
358 		cdns_ddr_set_port_bandwidth(ddr_ctrl_base, axi, 50, 1);
359 	}
360 
361 	/*
362 	 * The hardware requires that the valid address ranges must not overlap.
363 	 * So, we initialise all address ranges to be above the DDR, length 0.
364 	 */
365 	for (entry = 0; entry < DDR_NR_ENTRIES; entry++)
366 		cdns_ddr_enable_addr_range(ddr_ctrl_base, entry,
367 					   ddr_start_addr + ddr_size, 0);
368 
369 	for (i = 350; i <= 374; i++)
370 		ddrc_writel(*(reg350 - 350 + i), ddr_ctrl_base + i);
371 
372 	/* Disable optimised read-modify-write logic */
373 	ddrc_writeb(0, base8 + DDR_OPT_RMODW_REG);
374 
375 	/*
376 	 * Disable all interrupts, we are not handling them.
377 	 * For detail of the interrupt mask, ack and status bits, see the
378 	 * manual's description of the 'int_status' parameter.
379 	 */
380 	ddrc_writel(0, base8 + DDR_INTERRUPT_MASK);
381 
382 	/*
383 	 * Default settings to enable full access to the entire DDR.
384 	 * Users can set different ranges and access rights by calling these
385 	 * functions before calling cdns_ddr_ctrl_start().
386 	 */
387 	cdns_ddr_enable_addr_range(ddr_ctrl_base, 0,
388 				   ddr_start_addr, ddr_size);
389 	cdns_ddr_enable_prot(ddr_ctrl_base, 0, CDNS_DDR_RANGE_PROT_BITS_FULL,
390 			     0xffff, 0xffff, 0x0f, 0x0f);
391 }
392 
cdns_ddr_ctrl_start(void * ddr_ctrl_basex)393 void cdns_ddr_ctrl_start(void *ddr_ctrl_basex)
394 {
395 	u32 *ddr_ctrl_base = (u32 *)ddr_ctrl_basex;
396 	u8 *base8 = (u8 *)ddr_ctrl_basex;
397 
398 	/* Start */
399 	ddrc_writeb(1, base8 + DDR_START_REG);
400 
401 	/* Wait for controller to be ready (interrupt status) */
402 	wait_for_bit_le32(base8 + DDR_INTERRUPT_STATUS, 0x100, true, 1000, false);
403 
404 	/* clear all interrupts */
405 	ddrc_writel(~0, base8 + DDR_INTERRUPT_ACK);
406 
407 	/* Step 19 Wait 500us from MRESETB=1 */
408 	udelay(500);
409 
410 	/* Step 20 tCKSRX wait (From supply stable clock for MCK) */
411 	/* DENALI_CTL_19 TREF_ENABLE=0x1(=1), AREFRESH=0x1(=1) */
412 	ddrc_writel(0x01000100, ddr_ctrl_base + 19);
413 }
414