2 * SPDX-License-Identifier: GPL-2.0 IBM-pibs
5 #include <asm/ppc4xx.h>
7 #include <ppc_asm.tmpl>
10 #include <asm/cache.h>
13 /******************************************************************************
14 * Function: ext_bus_cntlr_init
16 * Description: Configures EBC Controller and a few basic chip selects.
18 * CS0 is setup to get the Boot Flash out of the addresss range
19 * so that we may setup a stack. CS7 is setup so that we can
20 * access and reset the hardware watchdog.
22 * IMPORTANT: For pass1 this code must run from
23 * cache since you can not reliably change a peripheral banks
24 * timing register (pbxap) while running code from that bank.
25 * For ex., since we are running from ROM on bank 0, we can NOT
26 * execute the code that modifies bank 0 timings from ROM, so
27 * we run it from cache.
29 * Notes: Does NOT use the stack.
30 *****************************************************************************/
33 .globl ext_bus_cntlr_init
34 .type ext_bus_cntlr_init, @function
37 /********************************************************************
38 * Prefetch entire ext_bus_cntrl_init function into the icache.
39 * This is necessary because we are going to change the same CS we
40 * are executing from. Otherwise a CPU lockup may occur.
41 *******************************************************************/
44 mflr r3 /* get address of ..getAddr */
46 /* Calculate number of cache lines for this function */
47 addi r4, 0, (((.Lfe0 - ..getAddr) / CONFIG_SYS_CACHELINE_SIZE) + 2)
50 icbt r0, r3 /* prefetch cache line for addr in r3*/
51 addi r3, r3, CONFIG_SYS_CACHELINE_SIZE /* move to next cache line */
52 bdnz ..ebcloop /* continue for $CTR cache lines */
54 /********************************************************************
55 * Delay to ensure all accesses to ROM are complete before changing
56 * bank 0 timings. 200usec should be enough.
57 * 200,000,000 (cycles/sec) X .000200 (sec) = 0x9C40 cycles.
58 *******************************************************************/
60 ori r3, r3, 0xA000 /* wait 200us from reset */
63 bdnz ..spinlp /* spin loop */
65 /********************************************************************
66 * Setup External Bus Controller (EBC).
67 *******************************************************************/
69 mtdcr EBC0_CFGADDR, r3
70 addis r4, 0, 0xb040 /* Device base timeout = 1024 cycles */
71 ori r4, r4, 0x0 /* Drive CS with external master */
72 mtdcr EBC0_CFGDATA, r4
74 /********************************************************************
75 * Change PCIINT signal to PerWE
76 *******************************************************************/
81 /********************************************************************
82 * Memory Bank 0 (Flash Bank 0) initialization
83 *******************************************************************/
85 mtdcr EBC0_CFGADDR, r3
86 addis r4, 0, CONFIG_SYS_W7O_EBC_PB0AP@h
87 ori r4, r4, CONFIG_SYS_W7O_EBC_PB0AP@l
88 mtdcr EBC0_CFGDATA, r4
91 mtdcr EBC0_CFGADDR, r3
92 addis r4, 0, CONFIG_SYS_W7O_EBC_PB0CR@h
93 ori r4, r4, CONFIG_SYS_W7O_EBC_PB0CR@l
94 mtdcr EBC0_CFGDATA, r4
96 /********************************************************************
97 * Memory Bank 7 LEDs - NEEDED BECAUSE OF HW WATCHDOG AND LEDs.
98 *******************************************************************/
100 mtdcr EBC0_CFGADDR, r3
101 addis r4, 0, CONFIG_SYS_W7O_EBC_PB7AP@h
102 ori r4, r4, CONFIG_SYS_W7O_EBC_PB7AP@l
103 mtdcr EBC0_CFGDATA, r4
106 mtdcr EBC0_CFGADDR, r3
107 addis r4, 0, CONFIG_SYS_W7O_EBC_PB7CR@h
108 ori r4, r4, CONFIG_SYS_W7O_EBC_PB7CR@l
109 mtdcr EBC0_CFGDATA, r4
111 /* We are all done */
112 mtlr r0 /* Restore link register */
113 blr /* Return to calling function */
114 .Lfe0: .size ext_bus_cntlr_init,.Lfe0-ext_bus_cntlr_init
115 /* end ext_bus_cntlr_init() */
117 /******************************************************************************
118 * Function: sdram_init
120 * Description: Configures SDRAM memory banks.
122 * Serial Presence Detect, "SPD," reads the SDRAM EEPROM
123 * via the IIC bus and then configures the SDRAM memory
124 * banks appropriately. If Auto Memory Configuration is
125 * is not used, it is assumed that a 4MB 11x8x2, non-ECC,
126 * SDRAM is soldered down.
128 * Notes: Expects that the stack is already setup.
129 *****************************************************************************/
133 .type sdram_init, @function
135 /* save the return info on stack */
136 mflr r0 /* Get link register */
137 stwu r1, -8(r1) /* Save back chain and move SP */
138 stw r0, +12(r1) /* Save link register */
141 * First call spd_sdram to try to init SDRAM according to the
142 * contents of the SPD EEPROM. If the SPD EEPROM is blank or
143 * erronious, spd_sdram returns 0 in R3.
147 addic. r3, r3, 0 /* Check for error, save dram size */
148 bne ..sdri_done /* If it worked, we're done... */
150 /********************************************************************
151 * If SPD detection fails, we'll default to 4MB, 11x8x2, as this
152 * is the SMALLEST SDRAM size the 405 supports. We can do this
153 * because W7O boards have soldered on RAM, and there will always
154 * be some amount present. If we were using DIMMs, we should hang
155 * the board instead, since it doesn't have any RAM to continue
157 *******************************************************************/
160 * Disable memory controller to allow
161 * values to be changed.
163 addi r3, 0, SDRAM0_CFG
164 mtdcr SDRAM0_CFGADDR, r3
167 mtdcr SDRAM0_CFGDATA, r4
170 * Set MB0CF for ext bank 0. (0-4MB) Address Mode 5 since 11x8x2
171 * All other banks are disabled.
173 addi r3, 0, SDRAM0_B0CR
174 mtdcr SDRAM0_CFGADDR, r3
175 addis r4, 0, 0x0000 /* BA=0x0, SZ=4MB */
176 ori r4, r4, 0x8001 /* Mode is 5, 11x8x2or4, BE=Enabled */
177 mtdcr SDRAM0_CFGDATA, r4
179 /* Clear MB1CR,MB2CR,MB3CR to turn other banks off */
180 addi r4, 0, 0 /* Zero the data reg */
182 addi r3, r3, 4 /* Point to MB1CF reg */
183 mtdcr SDRAM0_CFGADDR, r3 /* Set the address */
184 mtdcr SDRAM0_CFGDATA, r4 /* Zero the reg */
186 addi r3, r3, 4 /* Point to MB2CF reg */
187 mtdcr SDRAM0_CFGADDR, r3 /* Set the address */
188 mtdcr SDRAM0_CFGDATA, r4 /* Zero the reg */
190 addi r3, r3, 4 /* Point to MB3CF reg */
191 mtdcr SDRAM0_CFGADDR, r3 /* Set the address */
192 mtdcr SDRAM0_CFGDATA, r4 /* Zero the reg */
194 /********************************************************************
195 * Set the SDRAM Timing reg, SDTR1 and the refresh timer reg, RTR.
196 * To set the appropriate timings, we assume sdram is
197 * 100MHz (pc100 compliant).
198 *******************************************************************/
203 addi r3, 0, SDRAM0_TR
204 mtdcr SDRAM0_CFGADDR, r3
205 addis r4, 0, 0x0086 /* SDTR1 value for 100Mhz */
207 mtdcr SDRAM0_CFGDATA, r4
212 addi r3, 0, SDRAM0_RTR
213 mtdcr SDRAM0_CFGADDR, r3
214 addis r4, 0, 0x05F0 /* RTR refresh val = 15.625ms@100Mhz */
215 mtdcr SDRAM0_CFGDATA, r4
217 /********************************************************************
218 * Delay to ensure 200usec have elapsed since reset. Assume worst
219 * case that the core is running 200Mhz:
220 * 200,000,000 (cycles/sec) X .000200 (sec) = 0x9C40 cycles
221 *******************************************************************/
223 ori r3, r3, 0xA000 /* Wait 200us from reset */
226 bdnz ..spinlp2 /* spin loop */
228 /********************************************************************
229 * Set memory controller options reg, MCOPT1.
230 *******************************************************************/
231 addi r3, 0, SDRAM0_CFG
232 mtdcr SDRAM0_CFGADDR, r3
233 addis r4, 0, 0x80E0 /* DC_EN=1,SRE=0,PME=0,MEMCHK=0 */
234 ori r4, r4, 0x0000 /* REGEN=0,DRW=00,BRPF=01,ECCDD=1 */
235 mtdcr SDRAM0_CFGDATA, r4 /* EMDULR=1 */
238 /* restore and return */
239 lwz r0, +12(r1) /* Get saved link register */
240 addi r1, r1, +8 /* Remove frame from stack */
241 mtlr r0 /* Restore link register */
242 blr /* Return to calling function */
243 .Lfe1: .size sdram_init,.Lfe1-sdram_init
244 /* end sdram_init() */