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 <common.h>
28 #include <linux/delay.h>
29 #include <linux/sizes.h>
30 #include <asm/io.h>
31 #include <wait_bit.h>
32 #include <renesas/ddr_ctrl.h>
33 
34 /* avoid warning for real pr_debug in <linux/printk.h> */
35 #ifdef pr_debug
36 #undef pr_debug
37 #endif
38 
39 #ifdef DEBUG
40 	#define pr_debug(fmt, args...)	printf(fmt, ##args)
41 	#define pr_debug2(fmt, args...)	printf(fmt, ##args)
42 #else
43 	#define pr_debug(fmt, args...)
44 	#define pr_debug2(fmt, args...)
45 #endif
46 
47 #define DDR_NR_AXI_PORTS		4
48 #define DDR_NR_ENTRIES			16
49 
50 #define DDR_START_REG			(0)		/* DENALI_CTL_00 */
51 #define DDR_CS0_MR1_REG			(32 * 4)	/* DENALI_CTL_32 */
52 #define DDR_CS0_MR2_REG			(32 * 4 + 2)	/* DENALI_CTL_32 */
53 #define DDR_CS1_MR1_REG			(34 * 4 + 2)	/* DENALI_CTL_34 */
54 #define DDR_CS1_MR2_REG			(35 * 4)	/* DENALI_CTL_35 */
55 #define DDR_ECC_ENABLE_REG		(36 * 4 + 2)	/* DENALI_CTL_36 */
56 #define DDR_ECC_DISABLE_W_UC_ERR_REG	(37 * 4 + 2)	/* DENALI_CTL_37 */
57 #define DDR_HALF_DATAPATH_REG		(54 * 4)	/* DENALI_CTL_54 */
58 #define DDR_INTERRUPT_STATUS		(56 * 4)	/* DENALI_CTL_56 */
59 #define DDR_INTERRUPT_ACK		(57 * 4)	/* DENALI_CTL_57 */
60 #define DDR_INTERRUPT_MASK		(58 * 4)	/* DENALI_CTL_58 */
61 #define DDR_CS0_ODT_MAP_REG		(62 * 4 + 2)	/* DENALI_CTL_62 */
62 #define DDR_CS1_ODT_MAP_REG		(63 * 4)	/* DENALI_CTL_63 */
63 #define DDR_ODT_TODTL_2CMD		(63 * 4 + 2)	/* DENALI_CTL_63 */
64 #define DDR_ODT_TODTH_WR		(63 * 4 + 3)	/* DENALI_CTL_63 */
65 #define DDR_ODT_TODTH_RD		(64 * 4 + 0)	/* DENALI_CTL_64 */
66 #define DDR_ODT_EN			(64 * 4 + 1)	/* DENALI_CTL_64 */
67 #define DDR_ODT_WR_TO_ODTH		(64 * 4 + 2)	/* DENALI_CTL_64 */
68 #define DDR_ODT_RD_TO_ODTH		(64 * 4 + 3)	/* DENALI_CTL_64 */
69 #define DDR_DIFF_CS_DELAY_REG		(66 * 4)	/* DENALI_CTL_66 */
70 #define DDR_SAME_CS_DELAY_REG		(67 * 4)	/* DENALI_CTL_67 */
71 #define DDR_RW_PRIORITY_REGS		(87 * 4 + 2)	/* DENALI_CTL_87 */
72 #define DDR_RW_FIFO_TYPE_REGS		(88 * 4)	/* DENALI_CTL_88 */
73 #define DDR_AXI_PORT_PROT_ENABLE_REG	(90 * 4 + 3)	/* DENALI_CTL_90 */
74 #define DDR_ADDR_RANGE_REGS		(91 * 4)	/* DENALI_CTL_91 */
75 #define DDR_RANGE_PROT_REGS		(218 * 4 + 2)	/* DENALI_CTL_218 */
76 #define DDR_ARB_CMD_Q_THRESHOLD_REG	(346 * 4 + 2)	/* DENALI_CTL_346 */
77 #define DDR_AXI_PORT_BANDWIDTH_REG	(346 * 4 + 3)	/* DENALI_CTL_346 */
78 #define DDR_OPT_RMODW_REG		(372 * 4 + 3)	/* DENALI_CTL_372 */
79 
ddrc_writeb(u8 val,void * p)80 static void ddrc_writeb(u8 val, void *p)
81 {
82 	pr_debug2("DDR: %p = 0x%02x\n", p, val);
83 	writeb(val, p);
84 }
85 
ddrc_writew(u16 val,void * p)86 static void ddrc_writew(u16 val, void *p)
87 {
88 	pr_debug2("DDR: %p = 0x%04x\n", p, val);
89 	writew(val, p);
90 }
91 
ddrc_writel(u32 val,void * p)92 static void ddrc_writel(u32 val, void *p)
93 {
94 	pr_debug2("DDR: %p = 0x%08x\n", p, val);
95 	writel(val, p);
96 }
97 
cdns_ddr_set_mr1(void * base,int cs,u16 odt_impedance,u16 drive_strength)98 void cdns_ddr_set_mr1(void *base, int cs, u16 odt_impedance, u16 drive_strength)
99 {
100 	void *reg;
101 	u16 tmp;
102 
103 	if (cs == 0)
104 		reg = (u8 *)base + DDR_CS0_MR1_REG;
105 	else
106 		reg = (u8 *)base + DDR_CS1_MR1_REG;
107 
108 	tmp = readw(reg);
109 
110 	tmp &= ~MODE_REGISTER_MASK;
111 	tmp |=  MODE_REGISTER_MR1;
112 
113 	tmp &= ~MR1_ODT_IMPEDANCE_MASK;
114 	tmp |=  odt_impedance;
115 
116 	tmp &= ~MR1_DRIVE_STRENGTH_MASK;
117 	tmp |=  drive_strength;
118 
119 	writew(tmp, reg);
120 }
121 
cdns_ddr_set_mr2(void * base,int cs,u16 dynamic_odt,u16 self_refresh_temp)122 void cdns_ddr_set_mr2(void *base, int cs, u16 dynamic_odt, u16 self_refresh_temp)
123 {
124 	void *reg;
125 	u16 tmp;
126 
127 	if (cs == 0)
128 		reg = (u8 *)base + DDR_CS0_MR2_REG;
129 	else
130 		reg = (u8 *)base + DDR_CS1_MR2_REG;
131 
132 	tmp = readw(reg);
133 
134 	tmp &= ~MODE_REGISTER_MASK;
135 	tmp |=  MODE_REGISTER_MR2;
136 
137 	tmp &= ~MR2_DYNAMIC_ODT_MASK;
138 	tmp |=  dynamic_odt;
139 
140 	tmp &= ~MR2_SELF_REFRESH_TEMP_MASK;
141 	tmp |=  self_refresh_temp;
142 
143 	writew(tmp, reg);
144 }
145 
cdns_ddr_set_odt_map(void * base,int cs,u16 odt_map)146 void cdns_ddr_set_odt_map(void *base, int cs, u16 odt_map)
147 {
148 	void *reg;
149 
150 	if (cs == 0)
151 		reg = (u8 *)base + DDR_CS0_ODT_MAP_REG;
152 	else
153 		reg = (u8 *)base + DDR_CS1_ODT_MAP_REG;
154 
155 	writew(odt_map, reg);
156 }
157 
cdns_ddr_set_odt_times(void * base,u8 TODTL_2CMD,u8 TODTH_WR,u8 TODTH_RD,u8 WR_TO_ODTH,u8 RD_TO_ODTH)158 void cdns_ddr_set_odt_times(void *base, u8 TODTL_2CMD, u8 TODTH_WR, u8 TODTH_RD,
159 			    u8 WR_TO_ODTH, u8 RD_TO_ODTH)
160 {
161 	writeb(TODTL_2CMD,	(u8 *)base + DDR_ODT_TODTL_2CMD);
162 	writeb(TODTH_WR,	(u8 *)base + DDR_ODT_TODTH_WR);
163 	writeb(TODTH_RD,	(u8 *)base + DDR_ODT_TODTH_RD);
164 	writeb(1,		(u8 *)base + DDR_ODT_EN);
165 	writeb(WR_TO_ODTH,	(u8 *)base + DDR_ODT_WR_TO_ODTH);
166 	writeb(RD_TO_ODTH,	(u8 *)base + DDR_ODT_RD_TO_ODTH);
167 }
168 
cdns_ddr_set_same_cs_delays(void * base,u8 r2r,u8 r2w,u8 w2r,u8 w2w)169 void cdns_ddr_set_same_cs_delays(void *base, u8 r2r, u8 r2w, u8 w2r, u8 w2w)
170 {
171 	u32 val = (w2w << 24) | (w2r << 16) | (r2w << 8) | r2r;
172 
173 	writel(val, (u8 *)base + DDR_SAME_CS_DELAY_REG);
174 }
175 
cdns_ddr_set_diff_cs_delays(void * base,u8 r2r,u8 r2w,u8 w2r,u8 w2w)176 void cdns_ddr_set_diff_cs_delays(void *base, u8 r2r, u8 r2w, u8 w2r, u8 w2w)
177 {
178 	u32 val = (w2w << 24) | (w2r << 16) | (r2w << 8) | r2r;
179 
180 	writel(val, (u8 *)base + DDR_DIFF_CS_DELAY_REG);
181 }
182 
cdns_ddr_set_port_rw_priority(void * base,int port,u8 read_pri,u8 write_pri)183 void cdns_ddr_set_port_rw_priority(void *base, int port,
184 				   u8 read_pri, u8 write_pri)
185 {
186 	u8 *reg8 = (u8 *)base + DDR_RW_PRIORITY_REGS;
187 
188 	reg8 += (port * 3);
189 	pr_debug("%s port %d (reg8=%p, DENALI_CTL_%d)\n",
190 		 __func__, port, reg8, (reg8 - (u8 *)base) / 4);
191 
192 	ddrc_writeb(read_pri, reg8++);
193 	ddrc_writeb(write_pri, reg8++);
194 }
195 
196 /* The DDR Controller has 16 entries. Each entry can specify an allowed address
197  * range (with 16KB resolution) for one of the 4 AXI slave ports.
198  */
cdns_ddr_enable_port_addr_range(void * base,int port,int entry,u32 addr_start,u32 size)199 void cdns_ddr_enable_port_addr_range(void *base, int port, int entry,
200 				     u32 addr_start, u32 size)
201 {
202 	u32 addr_end;
203 	u32 *reg32 = (u32 *)((u8 *)base + DDR_ADDR_RANGE_REGS);
204 	u32 tmp;
205 
206 	reg32 += (port * DDR_NR_ENTRIES * 2);
207 	reg32 += (entry * 2);
208 	pr_debug("%s port %d, entry %d (reg32=%p, DENALI_CTL_%d)\n",
209 		 __func__, port, entry, reg32, ((u8 *)reg32 - (u8 *)base) / 4);
210 
211 	/* These registers represent 16KB address blocks */
212 	addr_start /= SZ_16K;
213 	size /= SZ_16K;
214 	if (size)
215 		addr_end = addr_start + size - 1;
216 	else
217 		addr_end = addr_start;
218 
219 	ddrc_writel(addr_start, reg32++);
220 
221 	/*
222 	 * end_addr: Ensure we only set the bottom 18-bits as DENALI_CTL_218
223 	 * also contains the AXI0 range protection bits.
224 	 */
225 	tmp = readl(reg32);
226 	tmp &= ~(BIT(18) - 1);
227 	tmp |= addr_end;
228 	ddrc_writel(tmp, reg32);
229 }
230 
cdns_ddr_enable_addr_range(void * base,int entry,u32 addr_start,u32 size)231 void cdns_ddr_enable_addr_range(void *base, int entry,
232 				u32 addr_start, u32 size)
233 {
234 	int axi;
235 
236 	for (axi = 0; axi < DDR_NR_AXI_PORTS; axi++)
237 		cdns_ddr_enable_port_addr_range(base, axi, entry,
238 						addr_start, size);
239 }
240 
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)241 void cdns_ddr_enable_port_prot(void *base, int port, int entry,
242 			       enum cdns_ddr_range_prot range_protection_bits,
243 			       u16 range_RID_check_bits,
244 			       u16 range_WID_check_bits,
245 			       u8 range_RID_check_bits_ID_lookup,
246 			       u8 range_WID_check_bits_ID_lookup)
247 {
248 	/*
249 	 * Technically, the offset here points to the byte before the start of
250 	 * the range protection registers. However, all entries consist of 8
251 	 * bytes, except the first one (which is missing a padding byte) so we
252 	 * work around that subtlely.
253 	 */
254 	u8 *reg8 = (u8 *)base + DDR_RANGE_PROT_REGS;
255 
256 	reg8 += (port * DDR_NR_ENTRIES * 8);
257 	reg8 += (entry * 8);
258 	pr_debug("%s port %d, entry %d (reg8=%p, DENALI_CTL_%d)\n",
259 		 __func__, port, entry, reg8, (reg8 - (u8 *)base) / 4);
260 
261 	if (port == 0 && entry == 0)
262 		ddrc_writeb(range_protection_bits, reg8 + 1);
263 	else
264 		ddrc_writeb(range_protection_bits, reg8);
265 
266 	ddrc_writew(range_RID_check_bits, reg8 + 2);
267 	ddrc_writew(range_WID_check_bits, reg8 + 4);
268 	ddrc_writeb(range_RID_check_bits_ID_lookup, reg8 + 6);
269 	ddrc_writeb(range_WID_check_bits_ID_lookup, reg8 + 7);
270 }
271 
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)272 void cdns_ddr_enable_prot(void *base, int entry,
273 			  enum cdns_ddr_range_prot range_protection_bits,
274 			  u16 range_RID_check_bits,
275 			  u16 range_WID_check_bits,
276 			  u8 range_RID_check_bits_ID_lookup,
277 			  u8 range_WID_check_bits_ID_lookup)
278 {
279 	int axi;
280 
281 	for (axi = 0; axi < DDR_NR_AXI_PORTS; axi++)
282 		cdns_ddr_enable_port_prot(base, axi, entry,
283 					  range_protection_bits,
284 					  range_RID_check_bits,
285 					  range_WID_check_bits,
286 					  range_RID_check_bits_ID_lookup,
287 					  range_WID_check_bits_ID_lookup);
288 }
289 
cdns_ddr_set_port_bandwidth(void * base,int port,u8 max_percent,u8 overflow_ok)290 void cdns_ddr_set_port_bandwidth(void *base, int port,
291 				 u8 max_percent, u8 overflow_ok)
292 {
293 	u8 *reg8 = (u8 *)base + DDR_AXI_PORT_BANDWIDTH_REG;
294 
295 	reg8 += (port * 3);
296 	pr_debug("%s port %d, (reg8=%p, DENALI_CTL_%d)\n",
297 		 __func__, port, reg8, (reg8 - (u8 *)base) / 4);
298 
299 	ddrc_writeb(max_percent, reg8++);	/* Maximum bandwidth percentage */
300 	ddrc_writeb(overflow_ok, reg8++);	/* Bandwidth overflow allowed */
301 }
302 
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)303 void cdns_ddr_ctrl_init(void *ddr_ctrl_basex, int async,
304 			const u32 *reg0, const u32 *reg350,
305 			u32 ddr_start_addr, u32 ddr_size,
306 			int enable_ecc, int enable_8bit)
307 {
308 	int i, axi, entry;
309 	u32 *ddr_ctrl_base = (u32 *)ddr_ctrl_basex;
310 	u8 *base8 = (u8 *)ddr_ctrl_basex;
311 
312 	ddrc_writel(*reg0, ddr_ctrl_base + 0);
313 	/* 1 to 6 are read only */
314 	for (i = 7; i <= 26; i++)
315 		ddrc_writel(*(reg0 + i), ddr_ctrl_base + i);
316 	/* 27 to 29 are not changed */
317 	for (i = 30; i <= 87; i++)
318 		ddrc_writel(*(reg0 + i), ddr_ctrl_base + i);
319 
320 	/* Enable/disable ECC */
321 	if (enable_ecc) {
322 		pr_debug("%s enabling ECC\n", __func__);
323 		ddrc_writeb(1, base8 + DDR_ECC_ENABLE_REG);
324 	} else {
325 		ddrc_writeb(0, base8 + DDR_ECC_ENABLE_REG);
326 	}
327 
328 	/* ECC: Disable corruption for read/modify/write operations */
329 	ddrc_writeb(1, base8 + DDR_ECC_DISABLE_W_UC_ERR_REG);
330 
331 	/* Set 8/16-bit data width using reduce bit (enable half datapath)*/
332 	if (enable_8bit) {
333 		pr_debug("%s using 8-bit data\n", __func__);
334 		ddrc_writeb(1, base8 + DDR_HALF_DATAPATH_REG);
335 	} else {
336 		ddrc_writeb(0, base8 + DDR_HALF_DATAPATH_REG);
337 	}
338 
339 	/* Threshold for command queue */
340 	ddrc_writeb(4, base8 + DDR_ARB_CMD_Q_THRESHOLD_REG);
341 
342 	/* AXI port protection => enable */
343 	ddrc_writeb(0x01, base8 + DDR_AXI_PORT_PROT_ENABLE_REG);
344 
345 	/* Set port interface type, default port priority and bandwidths */
346 	for (axi = 0; axi < DDR_NR_AXI_PORTS; axi++) {
347 		/* port interface type: synchronous or asynchronous AXI clock */
348 		u8 *fifo_reg = base8 + DDR_RW_FIFO_TYPE_REGS + (axi * 3);
349 
350 		if (async)
351 			ddrc_writeb(0, fifo_reg);
352 		else
353 			ddrc_writeb(3, fifo_reg);
354 
355 		/* R/W priorities */
356 		cdns_ddr_set_port_rw_priority(ddr_ctrl_base, axi, 2, 2);
357 
358 		/* AXI bandwidth */
359 		cdns_ddr_set_port_bandwidth(ddr_ctrl_base, axi, 50, 1);
360 	}
361 
362 	/*
363 	 * The hardware requires that the valid address ranges must not overlap.
364 	 * So, we initialise all address ranges to be above the DDR, length 0.
365 	 */
366 	for (entry = 0; entry < DDR_NR_ENTRIES; entry++)
367 		cdns_ddr_enable_addr_range(ddr_ctrl_base, entry,
368 					   ddr_start_addr + ddr_size, 0);
369 
370 	for (i = 350; i <= 374; i++)
371 		ddrc_writel(*(reg350 - 350 + i), ddr_ctrl_base + i);
372 
373 	/* Disable optimised read-modify-write logic */
374 	ddrc_writeb(0, base8 + DDR_OPT_RMODW_REG);
375 
376 	/*
377 	 * Disable all interrupts, we are not handling them.
378 	 * For detail of the interrupt mask, ack and status bits, see the
379 	 * manual's description of the 'int_status' parameter.
380 	 */
381 	ddrc_writel(0, base8 + DDR_INTERRUPT_MASK);
382 
383 	/*
384 	 * Default settings to enable full access to the entire DDR.
385 	 * Users can set different ranges and access rights by calling these
386 	 * functions before calling cdns_ddr_ctrl_start().
387 	 */
388 	cdns_ddr_enable_addr_range(ddr_ctrl_base, 0,
389 				   ddr_start_addr, ddr_size);
390 	cdns_ddr_enable_prot(ddr_ctrl_base, 0, CDNS_DDR_RANGE_PROT_BITS_FULL,
391 			     0xffff, 0xffff, 0x0f, 0x0f);
392 }
393 
cdns_ddr_ctrl_start(void * ddr_ctrl_basex)394 void cdns_ddr_ctrl_start(void *ddr_ctrl_basex)
395 {
396 	u32 *ddr_ctrl_base = (u32 *)ddr_ctrl_basex;
397 	u8 *base8 = (u8 *)ddr_ctrl_basex;
398 
399 	/* Start */
400 	ddrc_writeb(1, base8 + DDR_START_REG);
401 
402 	/* Wait for controller to be ready (interrupt status) */
403 	wait_for_bit_le32(base8 + DDR_INTERRUPT_STATUS, 0x100, true, 1000, false);
404 
405 	/* clear all interrupts */
406 	ddrc_writel(~0, base8 + DDR_INTERRUPT_ACK);
407 
408 	/* Step 19 Wait 500us from MRESETB=1 */
409 	udelay(500);
410 
411 	/* Step 20 tCKSRX wait (From supply stable clock for MCK) */
412 	/* DENALI_CTL_19 TREF_ENABLE=0x1(=1), AREFRESH=0x1(=1) */
413 	ddrc_writel(0x01000100, ddr_ctrl_base + 19);
414 }
415