xref: /linux/arch/arm/mach-omap2/omap4-common.c (revision c9933d494c54f72290831191c09bb8488bfd5905)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * OMAP4 specific common source file.
4  *
5  * Copyright (C) 2010 Texas Instruments, Inc.
6  * Author:
7  *	Santosh Shilimkar <santosh.shilimkar@ti.com>
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/init.h>
12 #include <linux/io.h>
13 #include <linux/irq.h>
14 #include <linux/irqchip.h>
15 #include <linux/platform_device.h>
16 #include <linux/memblock.h>
17 #include <linux/of_irq.h>
18 #include <linux/of_platform.h>
19 #include <linux/export.h>
20 #include <linux/irqchip/arm-gic.h>
21 #include <linux/of_address.h>
22 #include <linux/reboot.h>
23 #include <linux/genalloc.h>
24 
25 #include <asm/hardware/cache-l2x0.h>
26 #include <asm/mach/map.h>
27 #include <asm/memblock.h>
28 #include <asm/smp_twd.h>
29 
30 #include "omap-wakeupgen.h"
31 #include "soc.h"
32 #include "iomap.h"
33 #include "common.h"
34 #include "prminst44xx.h"
35 #include "prcm_mpu44xx.h"
36 #include "omap4-sar-layout.h"
37 #include "omap-secure.h"
38 #include "sram.h"
39 
40 #ifdef CONFIG_CACHE_L2X0
41 static void __iomem *l2cache_base;
42 #endif
43 
44 static void __iomem *sar_ram_base;
45 static void __iomem *gic_dist_base_addr;
46 static void __iomem *twd_base;
47 
48 #define IRQ_LOCALTIMER		29
49 
50 #ifdef CONFIG_OMAP_INTERCONNECT_BARRIER
51 
52 /* Used to implement memory barrier on DRAM path */
53 #define OMAP4_DRAM_BARRIER_VA			0xfe600000
54 
55 static void __iomem *dram_sync, *sram_sync;
56 static phys_addr_t dram_sync_paddr;
57 static u32 dram_sync_size;
58 
59 /*
60  * The OMAP4 bus structure contains asynchronous bridges which can buffer
61  * data writes from the MPU. These asynchronous bridges can be found on
62  * paths between the MPU to EMIF, and the MPU to L3 interconnects.
63  *
64  * We need to be careful about re-ordering which can happen as a result
65  * of different accesses being performed via different paths, and
66  * therefore different asynchronous bridges.
67  */
68 
69 /*
70  * OMAP4 interconnect barrier which is called for each mb() and wmb().
71  * This is to ensure that normal paths to DRAM (normal memory, cacheable
72  * accesses) are properly synchronised with writes to DMA coherent memory
73  * (normal memory, uncacheable) and device writes.
74  *
75  * The mb() and wmb() barriers only operate only on the MPU->MA->EMIF
76  * path, as we need to ensure that data is visible to other system
77  * masters prior to writes to those system masters being seen.
78  *
79  * Note: the SRAM path is not synchronised via mb() and wmb().
80  */
81 static void omap4_mb(void)
82 {
83 	if (dram_sync)
84 		writel_relaxed(0, dram_sync);
85 }
86 
87 /*
88  * OMAP4 Errata i688 - asynchronous bridge corruption when entering WFI.
89  *
90  * If a data is stalled inside asynchronous bridge because of back
91  * pressure, it may be accepted multiple times, creating pointer
92  * misalignment that will corrupt next transfers on that data path until
93  * next reset of the system. No recovery procedure once the issue is hit,
94  * the path remains consistently broken.
95  *
96  * Async bridges can be found on paths between MPU to EMIF and MPU to L3
97  * interconnects.
98  *
99  * This situation can happen only when the idle is initiated by a Master
100  * Request Disconnection (which is trigged by software when executing WFI
101  * on the CPU).
102  *
103  * The work-around for this errata needs all the initiators connected
104  * through an async bridge to ensure that data path is properly drained
105  * before issuing WFI. This condition will be met if one Strongly ordered
106  * access is performed to the target right before executing the WFI.
107  *
108  * In MPU case, L3 T2ASYNC FIFO and DDR T2ASYNC FIFO needs to be drained.
109  * IO barrier ensure that there is no synchronisation loss on initiators
110  * operating on both interconnect port simultaneously.
111  *
112  * This is a stronger version of the OMAP4 memory barrier below, and
113  * operates on both the MPU->MA->EMIF path but also the MPU->OCP path
114  * as well, and is necessary prior to executing a WFI.
115  */
116 void omap_interconnect_sync(void)
117 {
118 	if (dram_sync && sram_sync) {
119 		writel_relaxed(readl_relaxed(dram_sync), dram_sync);
120 		writel_relaxed(readl_relaxed(sram_sync), sram_sync);
121 		isb();
122 	}
123 }
124 
125 static int __init omap4_sram_init(void)
126 {
127 	struct device_node *np;
128 	struct gen_pool *sram_pool;
129 
130 	if (!soc_is_omap44xx() && !soc_is_omap54xx())
131 		return 0;
132 
133 	np = of_find_compatible_node(NULL, NULL, "ti,omap4-mpu");
134 	if (!np)
135 		pr_warn("%s:Unable to allocate sram needed to handle errata I688\n",
136 			__func__);
137 	sram_pool = of_gen_pool_get(np, "sram", 0);
138 	if (!sram_pool)
139 		pr_warn("%s:Unable to get sram pool needed to handle errata I688\n",
140 			__func__);
141 	else
142 		sram_sync = (void *)gen_pool_alloc(sram_pool, PAGE_SIZE);
143 
144 	return 0;
145 }
146 omap_arch_initcall(omap4_sram_init);
147 
148 /* Steal one page physical memory for barrier implementation */
149 void __init omap_barrier_reserve_memblock(void)
150 {
151 	dram_sync_size = ALIGN(PAGE_SIZE, SZ_1M);
152 	dram_sync_paddr = arm_memblock_steal(dram_sync_size, SZ_1M);
153 }
154 
155 void __init omap_barriers_init(void)
156 {
157 	struct map_desc dram_io_desc[1];
158 
159 	dram_io_desc[0].virtual = OMAP4_DRAM_BARRIER_VA;
160 	dram_io_desc[0].pfn = __phys_to_pfn(dram_sync_paddr);
161 	dram_io_desc[0].length = dram_sync_size;
162 	dram_io_desc[0].type = MT_MEMORY_RW_SO;
163 	iotable_init(dram_io_desc, ARRAY_SIZE(dram_io_desc));
164 	dram_sync = (void __iomem *) dram_io_desc[0].virtual;
165 
166 	pr_info("OMAP4: Map %pa to %p for dram barrier\n",
167 		&dram_sync_paddr, dram_sync);
168 
169 	soc_mb = omap4_mb;
170 }
171 
172 #endif
173 
174 void gic_dist_disable(void)
175 {
176 	if (gic_dist_base_addr)
177 		writel_relaxed(0x0, gic_dist_base_addr + GIC_DIST_CTRL);
178 }
179 
180 void gic_dist_enable(void)
181 {
182 	if (gic_dist_base_addr)
183 		writel_relaxed(0x1, gic_dist_base_addr + GIC_DIST_CTRL);
184 }
185 
186 bool gic_dist_disabled(void)
187 {
188 	return !(readl_relaxed(gic_dist_base_addr + GIC_DIST_CTRL) & 0x1);
189 }
190 
191 void gic_timer_retrigger(void)
192 {
193 	u32 twd_int = readl_relaxed(twd_base + TWD_TIMER_INTSTAT);
194 	u32 gic_int = readl_relaxed(gic_dist_base_addr + GIC_DIST_PENDING_SET);
195 	u32 twd_ctrl = readl_relaxed(twd_base + TWD_TIMER_CONTROL);
196 
197 	if (twd_int && !(gic_int & BIT(IRQ_LOCALTIMER))) {
198 		/*
199 		 * The local timer interrupt got lost while the distributor was
200 		 * disabled.  Ack the pending interrupt, and retrigger it.
201 		 */
202 		pr_warn("%s: lost localtimer interrupt\n", __func__);
203 		writel_relaxed(1, twd_base + TWD_TIMER_INTSTAT);
204 		if (!(twd_ctrl & TWD_TIMER_CONTROL_PERIODIC)) {
205 			writel_relaxed(1, twd_base + TWD_TIMER_COUNTER);
206 			twd_ctrl |= TWD_TIMER_CONTROL_ENABLE;
207 			writel_relaxed(twd_ctrl, twd_base + TWD_TIMER_CONTROL);
208 		}
209 	}
210 }
211 
212 #ifdef CONFIG_CACHE_L2X0
213 
214 void __iomem *omap4_get_l2cache_base(void)
215 {
216 	return l2cache_base;
217 }
218 
219 void omap4_l2c310_write_sec(unsigned long val, unsigned reg)
220 {
221 	unsigned smc_op;
222 
223 	switch (reg) {
224 	case L2X0_CTRL:
225 		smc_op = OMAP4_MON_L2X0_CTRL_INDEX;
226 		break;
227 
228 	case L2X0_AUX_CTRL:
229 		smc_op = OMAP4_MON_L2X0_AUXCTRL_INDEX;
230 		break;
231 
232 	case L2X0_DEBUG_CTRL:
233 		smc_op = OMAP4_MON_L2X0_DBG_CTRL_INDEX;
234 		break;
235 
236 	case L310_PREFETCH_CTRL:
237 		smc_op = OMAP4_MON_L2X0_PREFETCH_INDEX;
238 		break;
239 
240 	case L310_POWER_CTRL:
241 		pr_info_once("OMAP L2C310: ROM does not support power control setting\n");
242 		return;
243 
244 	default:
245 		WARN_ONCE(1, "OMAP L2C310: ignoring write to reg 0x%x\n", reg);
246 		return;
247 	}
248 
249 	omap_smc1(smc_op, val);
250 }
251 
252 int __init omap_l2_cache_init(void)
253 {
254 	/* Static mapping, never released */
255 	l2cache_base = ioremap(OMAP44XX_L2CACHE_BASE, SZ_4K);
256 	if (WARN_ON(!l2cache_base))
257 		return -ENOMEM;
258 	return 0;
259 }
260 #endif
261 
262 void __iomem *omap4_get_sar_ram_base(void)
263 {
264 	return sar_ram_base;
265 }
266 
267 /*
268  * SAR RAM used to save and restore the HW context in low power modes.
269  * Note that we need to initialize this very early for kexec. See
270  * omap4_mpuss_early_init().
271  */
272 void __init omap4_sar_ram_init(void)
273 {
274 	unsigned long sar_base;
275 
276 	/*
277 	 * To avoid code running on other OMAPs in
278 	 * multi-omap builds
279 	 */
280 	if (cpu_is_omap44xx())
281 		sar_base = OMAP44XX_SAR_RAM_BASE;
282 	else if (soc_is_omap54xx())
283 		sar_base = OMAP54XX_SAR_RAM_BASE;
284 	else
285 		return;
286 
287 	/* Static mapping, never released */
288 	sar_ram_base = ioremap(sar_base, SZ_16K);
289 	if (WARN_ON(!sar_ram_base))
290 		return;
291 }
292 
293 static const struct of_device_id intc_match[] = {
294 	{ .compatible = "ti,omap4-wugen-mpu", },
295 	{ .compatible = "ti,omap5-wugen-mpu", },
296 	{ },
297 };
298 
299 static struct device_node *intc_node;
300 
301 void __init omap_gic_of_init(void)
302 {
303 	struct device_node *np;
304 
305 	intc_node = of_find_matching_node(NULL, intc_match);
306 	if (WARN_ON(!intc_node)) {
307 		pr_err("No WUGEN found in DT, system will misbehave.\n");
308 		pr_err("UPDATE YOUR DEVICE TREE!\n");
309 	}
310 
311 	/* Extract GIC distributor and TWD bases for OMAP4460 ROM Errata WA */
312 	if (!cpu_is_omap446x())
313 		goto skip_errata_init;
314 
315 	np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-gic");
316 	gic_dist_base_addr = of_iomap(np, 0);
317 	of_node_put(np);
318 	WARN_ON(!gic_dist_base_addr);
319 
320 	np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-twd-timer");
321 	twd_base = of_iomap(np, 0);
322 	of_node_put(np);
323 	WARN_ON(!twd_base);
324 
325 skip_errata_init:
326 	irqchip_init();
327 }
328