xref: /openbmc/linux/arch/mips/ath25/ar2315.c (revision 827634ad)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 2003 Atheros Communications, Inc.,  All Rights Reserved.
7  * Copyright (C) 2006 FON Technology, SL.
8  * Copyright (C) 2006 Imre Kaloz <kaloz@openwrt.org>
9  * Copyright (C) 2006 Felix Fietkau <nbd@openwrt.org>
10  * Copyright (C) 2012 Alexandros C. Couloumbis <alex@ozo.com>
11  */
12 
13 /*
14  * Platform devices for Atheros AR2315 SoCs
15  */
16 
17 #include <linux/init.h>
18 #include <linux/kernel.h>
19 #include <linux/bitops.h>
20 #include <linux/irqdomain.h>
21 #include <linux/interrupt.h>
22 #include <linux/platform_device.h>
23 #include <linux/reboot.h>
24 #include <asm/bootinfo.h>
25 #include <asm/reboot.h>
26 #include <asm/time.h>
27 
28 #include <ath25_platform.h>
29 
30 #include "devices.h"
31 #include "ar2315.h"
32 #include "ar2315_regs.h"
33 
34 static void __iomem *ar2315_rst_base;
35 static struct irq_domain *ar2315_misc_irq_domain;
36 
37 static inline u32 ar2315_rst_reg_read(u32 reg)
38 {
39 	return __raw_readl(ar2315_rst_base + reg);
40 }
41 
42 static inline void ar2315_rst_reg_write(u32 reg, u32 val)
43 {
44 	__raw_writel(val, ar2315_rst_base + reg);
45 }
46 
47 static inline void ar2315_rst_reg_mask(u32 reg, u32 mask, u32 val)
48 {
49 	u32 ret = ar2315_rst_reg_read(reg);
50 
51 	ret &= ~mask;
52 	ret |= val;
53 	ar2315_rst_reg_write(reg, ret);
54 }
55 
56 static irqreturn_t ar2315_ahb_err_handler(int cpl, void *dev_id)
57 {
58 	ar2315_rst_reg_write(AR2315_AHB_ERR0, AR2315_AHB_ERROR_DET);
59 	ar2315_rst_reg_read(AR2315_AHB_ERR1);
60 
61 	pr_emerg("AHB fatal error\n");
62 	machine_restart("AHB error"); /* Catastrophic failure */
63 
64 	return IRQ_HANDLED;
65 }
66 
67 static struct irqaction ar2315_ahb_err_interrupt  = {
68 	.handler	= ar2315_ahb_err_handler,
69 	.name		= "ar2315-ahb-error",
70 };
71 
72 static void ar2315_misc_irq_handler(unsigned irq, struct irq_desc *desc)
73 {
74 	u32 pending = ar2315_rst_reg_read(AR2315_ISR) &
75 		      ar2315_rst_reg_read(AR2315_IMR);
76 	unsigned nr, misc_irq = 0;
77 
78 	if (pending) {
79 		struct irq_domain *domain = irq_get_handler_data(irq);
80 
81 		nr = __ffs(pending);
82 		misc_irq = irq_find_mapping(domain, nr);
83 	}
84 
85 	if (misc_irq) {
86 		if (nr == AR2315_MISC_IRQ_GPIO)
87 			ar2315_rst_reg_write(AR2315_ISR, AR2315_ISR_GPIO);
88 		else if (nr == AR2315_MISC_IRQ_WATCHDOG)
89 			ar2315_rst_reg_write(AR2315_ISR, AR2315_ISR_WD);
90 		generic_handle_irq(misc_irq);
91 	} else {
92 		spurious_interrupt();
93 	}
94 }
95 
96 static void ar2315_misc_irq_unmask(struct irq_data *d)
97 {
98 	ar2315_rst_reg_mask(AR2315_IMR, 0, BIT(d->hwirq));
99 }
100 
101 static void ar2315_misc_irq_mask(struct irq_data *d)
102 {
103 	ar2315_rst_reg_mask(AR2315_IMR, BIT(d->hwirq), 0);
104 }
105 
106 static struct irq_chip ar2315_misc_irq_chip = {
107 	.name		= "ar2315-misc",
108 	.irq_unmask	= ar2315_misc_irq_unmask,
109 	.irq_mask	= ar2315_misc_irq_mask,
110 };
111 
112 static int ar2315_misc_irq_map(struct irq_domain *d, unsigned irq,
113 			       irq_hw_number_t hw)
114 {
115 	irq_set_chip_and_handler(irq, &ar2315_misc_irq_chip, handle_level_irq);
116 	return 0;
117 }
118 
119 static struct irq_domain_ops ar2315_misc_irq_domain_ops = {
120 	.map = ar2315_misc_irq_map,
121 };
122 
123 /*
124  * Called when an interrupt is received, this function
125  * determines exactly which interrupt it was, and it
126  * invokes the appropriate handler.
127  *
128  * Implicitly, we also define interrupt priority by
129  * choosing which to dispatch first.
130  */
131 static void ar2315_irq_dispatch(void)
132 {
133 	u32 pending = read_c0_status() & read_c0_cause();
134 
135 	if (pending & CAUSEF_IP3)
136 		do_IRQ(AR2315_IRQ_WLAN0);
137 #ifdef CONFIG_PCI_AR2315
138 	else if (pending & CAUSEF_IP5)
139 		do_IRQ(AR2315_IRQ_LCBUS_PCI);
140 #endif
141 	else if (pending & CAUSEF_IP2)
142 		do_IRQ(AR2315_IRQ_MISC);
143 	else if (pending & CAUSEF_IP7)
144 		do_IRQ(ATH25_IRQ_CPU_CLOCK);
145 	else
146 		spurious_interrupt();
147 }
148 
149 void __init ar2315_arch_init_irq(void)
150 {
151 	struct irq_domain *domain;
152 	unsigned irq;
153 
154 	ath25_irq_dispatch = ar2315_irq_dispatch;
155 
156 	domain = irq_domain_add_linear(NULL, AR2315_MISC_IRQ_COUNT,
157 				       &ar2315_misc_irq_domain_ops, NULL);
158 	if (!domain)
159 		panic("Failed to add IRQ domain");
160 
161 	irq = irq_create_mapping(domain, AR2315_MISC_IRQ_AHB);
162 	setup_irq(irq, &ar2315_ahb_err_interrupt);
163 
164 	irq_set_chained_handler(AR2315_IRQ_MISC, ar2315_misc_irq_handler);
165 	irq_set_handler_data(AR2315_IRQ_MISC, domain);
166 
167 	ar2315_misc_irq_domain = domain;
168 }
169 
170 void __init ar2315_init_devices(void)
171 {
172 	/* Find board configuration */
173 	ath25_find_config(AR2315_SPI_READ_BASE, AR2315_SPI_READ_SIZE);
174 
175 	ath25_add_wmac(0, AR2315_WLAN0_BASE, AR2315_IRQ_WLAN0);
176 }
177 
178 static void ar2315_restart(char *command)
179 {
180 	void (*mips_reset_vec)(void) = (void *)0xbfc00000;
181 
182 	local_irq_disable();
183 
184 	/* try reset the system via reset control */
185 	ar2315_rst_reg_write(AR2315_COLD_RESET, AR2317_RESET_SYSTEM);
186 
187 	/* Cold reset does not work on the AR2315/6, use the GPIO reset bits
188 	 * a workaround. Give it some time to attempt a gpio based hardware
189 	 * reset (atheros reference design workaround) */
190 
191 	/* TODO: implement the GPIO reset workaround */
192 
193 	/* Some boards (e.g. Senao EOC-2610) don't implement the reset logic
194 	 * workaround. Attempt to jump to the mips reset location -
195 	 * the boot loader itself might be able to recover the system */
196 	mips_reset_vec();
197 }
198 
199 /*
200  * This table is indexed by bits 5..4 of the CLOCKCTL1 register
201  * to determine the predevisor value.
202  */
203 static int clockctl1_predivide_table[4] __initdata = { 1, 2, 4, 5 };
204 static int pllc_divide_table[5] __initdata = { 2, 3, 4, 6, 3 };
205 
206 static unsigned __init ar2315_sys_clk(u32 clock_ctl)
207 {
208 	unsigned int pllc_ctrl, cpu_div;
209 	unsigned int pllc_out, refdiv, fdiv, divby2;
210 	unsigned int clk_div;
211 
212 	pllc_ctrl = ar2315_rst_reg_read(AR2315_PLLC_CTL);
213 	refdiv = ATH25_REG_MS(pllc_ctrl, AR2315_PLLC_REF_DIV);
214 	refdiv = clockctl1_predivide_table[refdiv];
215 	fdiv = ATH25_REG_MS(pllc_ctrl, AR2315_PLLC_FDBACK_DIV);
216 	divby2 = ATH25_REG_MS(pllc_ctrl, AR2315_PLLC_ADD_FDBACK_DIV) + 1;
217 	pllc_out = (40000000 / refdiv) * (2 * divby2) * fdiv;
218 
219 	/* clkm input selected */
220 	switch (clock_ctl & AR2315_CPUCLK_CLK_SEL_M) {
221 	case 0:
222 	case 1:
223 		clk_div = ATH25_REG_MS(pllc_ctrl, AR2315_PLLC_CLKM_DIV);
224 		clk_div = pllc_divide_table[clk_div];
225 		break;
226 	case 2:
227 		clk_div = ATH25_REG_MS(pllc_ctrl, AR2315_PLLC_CLKC_DIV);
228 		clk_div = pllc_divide_table[clk_div];
229 		break;
230 	default:
231 		pllc_out = 40000000;
232 		clk_div = 1;
233 		break;
234 	}
235 
236 	cpu_div = ATH25_REG_MS(clock_ctl, AR2315_CPUCLK_CLK_DIV);
237 	cpu_div = cpu_div * 2 ?: 1;
238 
239 	return pllc_out / (clk_div * cpu_div);
240 }
241 
242 static inline unsigned ar2315_cpu_frequency(void)
243 {
244 	return ar2315_sys_clk(ar2315_rst_reg_read(AR2315_CPUCLK));
245 }
246 
247 static inline unsigned ar2315_apb_frequency(void)
248 {
249 	return ar2315_sys_clk(ar2315_rst_reg_read(AR2315_AMBACLK));
250 }
251 
252 void __init ar2315_plat_time_init(void)
253 {
254 	mips_hpt_frequency = ar2315_cpu_frequency() / 2;
255 }
256 
257 void __init ar2315_plat_mem_setup(void)
258 {
259 	void __iomem *sdram_base;
260 	u32 memsize, memcfg;
261 	u32 devid;
262 	u32 config;
263 
264 	/* Detect memory size */
265 	sdram_base = ioremap_nocache(AR2315_SDRAMCTL_BASE,
266 				     AR2315_SDRAMCTL_SIZE);
267 	memcfg = __raw_readl(sdram_base + AR2315_MEM_CFG);
268 	memsize   = 1 + ATH25_REG_MS(memcfg, AR2315_MEM_CFG_DATA_WIDTH);
269 	memsize <<= 1 + ATH25_REG_MS(memcfg, AR2315_MEM_CFG_COL_WIDTH);
270 	memsize <<= 1 + ATH25_REG_MS(memcfg, AR2315_MEM_CFG_ROW_WIDTH);
271 	memsize <<= 3;
272 	add_memory_region(0, memsize, BOOT_MEM_RAM);
273 	iounmap(sdram_base);
274 
275 	ar2315_rst_base = ioremap_nocache(AR2315_RST_BASE, AR2315_RST_SIZE);
276 
277 	/* Detect the hardware based on the device ID */
278 	devid = ar2315_rst_reg_read(AR2315_SREV) & AR2315_REV_CHIP;
279 	switch (devid) {
280 	case 0x91:	/* Need to check */
281 		ath25_soc = ATH25_SOC_AR2318;
282 		break;
283 	case 0x90:
284 		ath25_soc = ATH25_SOC_AR2317;
285 		break;
286 	case 0x87:
287 		ath25_soc = ATH25_SOC_AR2316;
288 		break;
289 	case 0x86:
290 	default:
291 		ath25_soc = ATH25_SOC_AR2315;
292 		break;
293 	}
294 	ath25_board.devid = devid;
295 
296 	/* Clear any lingering AHB errors */
297 	config = read_c0_config();
298 	write_c0_config(config & ~0x3);
299 	ar2315_rst_reg_write(AR2315_AHB_ERR0, AR2315_AHB_ERROR_DET);
300 	ar2315_rst_reg_read(AR2315_AHB_ERR1);
301 	ar2315_rst_reg_write(AR2315_WDT_CTRL, AR2315_WDT_CTRL_IGNORE);
302 
303 	_machine_restart = ar2315_restart;
304 }
305 
306 #ifdef CONFIG_PCI_AR2315
307 static struct resource ar2315_pci_res[] = {
308 	{
309 		.name = "ar2315-pci-ctrl",
310 		.flags = IORESOURCE_MEM,
311 		.start = AR2315_PCI_BASE,
312 		.end = AR2315_PCI_BASE + AR2315_PCI_SIZE - 1,
313 	},
314 	{
315 		.name = "ar2315-pci-ext",
316 		.flags = IORESOURCE_MEM,
317 		.start = AR2315_PCI_EXT_BASE,
318 		.end = AR2315_PCI_EXT_BASE + AR2315_PCI_EXT_SIZE - 1,
319 	},
320 	{
321 		.name = "ar2315-pci",
322 		.flags = IORESOURCE_IRQ,
323 		.start = AR2315_IRQ_LCBUS_PCI,
324 		.end = AR2315_IRQ_LCBUS_PCI,
325 	},
326 };
327 #endif
328 
329 void __init ar2315_arch_init(void)
330 {
331 	unsigned irq = irq_create_mapping(ar2315_misc_irq_domain,
332 					  AR2315_MISC_IRQ_UART0);
333 
334 	ath25_serial_setup(AR2315_UART0_BASE, irq, ar2315_apb_frequency());
335 
336 #ifdef CONFIG_PCI_AR2315
337 	if (ath25_soc == ATH25_SOC_AR2315) {
338 		/* Reset PCI DMA logic */
339 		ar2315_rst_reg_mask(AR2315_RESET, 0, AR2315_RESET_PCIDMA);
340 		msleep(20);
341 		ar2315_rst_reg_mask(AR2315_RESET, AR2315_RESET_PCIDMA, 0);
342 		msleep(20);
343 
344 		/* Configure endians */
345 		ar2315_rst_reg_mask(AR2315_ENDIAN_CTL, 0, AR2315_CONFIG_PCIAHB |
346 				    AR2315_CONFIG_PCIAHB_BRIDGE);
347 
348 		/* Configure as PCI host with DMA */
349 		ar2315_rst_reg_write(AR2315_PCICLK, AR2315_PCICLK_PLLC_CLKM |
350 				  (AR2315_PCICLK_IN_FREQ_DIV_6 <<
351 				   AR2315_PCICLK_DIV_S));
352 		ar2315_rst_reg_mask(AR2315_AHB_ARB_CTL, 0, AR2315_ARB_PCI);
353 		ar2315_rst_reg_mask(AR2315_IF_CTL, AR2315_IF_PCI_CLK_MASK |
354 				    AR2315_IF_MASK, AR2315_IF_PCI |
355 				    AR2315_IF_PCI_HOST | AR2315_IF_PCI_INTR |
356 				    (AR2315_IF_PCI_CLK_OUTPUT_CLK <<
357 				     AR2315_IF_PCI_CLK_SHIFT));
358 
359 		platform_device_register_simple("ar2315-pci", -1,
360 						ar2315_pci_res,
361 						ARRAY_SIZE(ar2315_pci_res));
362 	}
363 #endif
364 }
365