xref: /openbmc/linux/arch/mips/ath25/ar2315.c (revision d9fd5a71)
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/memblock.h>
23 #include <linux/platform_device.h>
24 #include <linux/reboot.h>
25 #include <asm/bootinfo.h>
26 #include <asm/reboot.h>
27 #include <asm/time.h>
28 
29 #include <ath25_platform.h>
30 
31 #include "devices.h"
32 #include "ar2315.h"
33 #include "ar2315_regs.h"
34 
35 static void __iomem *ar2315_rst_base;
36 static struct irq_domain *ar2315_misc_irq_domain;
37 
38 static inline u32 ar2315_rst_reg_read(u32 reg)
39 {
40 	return __raw_readl(ar2315_rst_base + reg);
41 }
42 
43 static inline void ar2315_rst_reg_write(u32 reg, u32 val)
44 {
45 	__raw_writel(val, ar2315_rst_base + reg);
46 }
47 
48 static inline void ar2315_rst_reg_mask(u32 reg, u32 mask, u32 val)
49 {
50 	u32 ret = ar2315_rst_reg_read(reg);
51 
52 	ret &= ~mask;
53 	ret |= val;
54 	ar2315_rst_reg_write(reg, ret);
55 }
56 
57 static irqreturn_t ar2315_ahb_err_handler(int cpl, void *dev_id)
58 {
59 	ar2315_rst_reg_write(AR2315_AHB_ERR0, AR2315_AHB_ERROR_DET);
60 	ar2315_rst_reg_read(AR2315_AHB_ERR1);
61 
62 	pr_emerg("AHB fatal error\n");
63 	machine_restart("AHB error"); /* Catastrophic failure */
64 
65 	return IRQ_HANDLED;
66 }
67 
68 static void ar2315_misc_irq_handler(struct irq_desc *desc)
69 {
70 	u32 pending = ar2315_rst_reg_read(AR2315_ISR) &
71 		      ar2315_rst_reg_read(AR2315_IMR);
72 	unsigned nr, misc_irq = 0;
73 
74 	if (pending) {
75 		struct irq_domain *domain = irq_desc_get_handler_data(desc);
76 
77 		nr = __ffs(pending);
78 		misc_irq = irq_find_mapping(domain, nr);
79 	}
80 
81 	if (misc_irq) {
82 		if (nr == AR2315_MISC_IRQ_GPIO)
83 			ar2315_rst_reg_write(AR2315_ISR, AR2315_ISR_GPIO);
84 		else if (nr == AR2315_MISC_IRQ_WATCHDOG)
85 			ar2315_rst_reg_write(AR2315_ISR, AR2315_ISR_WD);
86 		generic_handle_irq(misc_irq);
87 	} else {
88 		spurious_interrupt();
89 	}
90 }
91 
92 static void ar2315_misc_irq_unmask(struct irq_data *d)
93 {
94 	ar2315_rst_reg_mask(AR2315_IMR, 0, BIT(d->hwirq));
95 }
96 
97 static void ar2315_misc_irq_mask(struct irq_data *d)
98 {
99 	ar2315_rst_reg_mask(AR2315_IMR, BIT(d->hwirq), 0);
100 }
101 
102 static struct irq_chip ar2315_misc_irq_chip = {
103 	.name		= "ar2315-misc",
104 	.irq_unmask	= ar2315_misc_irq_unmask,
105 	.irq_mask	= ar2315_misc_irq_mask,
106 };
107 
108 static int ar2315_misc_irq_map(struct irq_domain *d, unsigned irq,
109 			       irq_hw_number_t hw)
110 {
111 	irq_set_chip_and_handler(irq, &ar2315_misc_irq_chip, handle_level_irq);
112 	return 0;
113 }
114 
115 static struct irq_domain_ops ar2315_misc_irq_domain_ops = {
116 	.map = ar2315_misc_irq_map,
117 };
118 
119 /*
120  * Called when an interrupt is received, this function
121  * determines exactly which interrupt it was, and it
122  * invokes the appropriate handler.
123  *
124  * Implicitly, we also define interrupt priority by
125  * choosing which to dispatch first.
126  */
127 static void ar2315_irq_dispatch(void)
128 {
129 	u32 pending = read_c0_status() & read_c0_cause();
130 
131 	if (pending & CAUSEF_IP3)
132 		do_IRQ(AR2315_IRQ_WLAN0);
133 #ifdef CONFIG_PCI_AR2315
134 	else if (pending & CAUSEF_IP5)
135 		do_IRQ(AR2315_IRQ_LCBUS_PCI);
136 #endif
137 	else if (pending & CAUSEF_IP2)
138 		do_IRQ(AR2315_IRQ_MISC);
139 	else if (pending & CAUSEF_IP7)
140 		do_IRQ(ATH25_IRQ_CPU_CLOCK);
141 	else
142 		spurious_interrupt();
143 }
144 
145 void __init ar2315_arch_init_irq(void)
146 {
147 	struct irq_domain *domain;
148 	unsigned irq;
149 
150 	ath25_irq_dispatch = ar2315_irq_dispatch;
151 
152 	domain = irq_domain_add_linear(NULL, AR2315_MISC_IRQ_COUNT,
153 				       &ar2315_misc_irq_domain_ops, NULL);
154 	if (!domain)
155 		panic("Failed to add IRQ domain");
156 
157 	irq = irq_create_mapping(domain, AR2315_MISC_IRQ_AHB);
158 	if (request_irq(irq, ar2315_ahb_err_handler, 0, "ar2315-ahb-error",
159 			NULL))
160 		pr_err("Failed to register ar2315-ahb-error interrupt\n");
161 
162 	irq_set_chained_handler_and_data(AR2315_IRQ_MISC,
163 					 ar2315_misc_irq_handler, domain);
164 
165 	ar2315_misc_irq_domain = domain;
166 }
167 
168 void __init ar2315_init_devices(void)
169 {
170 	/* Find board configuration */
171 	ath25_find_config(AR2315_SPI_READ_BASE, AR2315_SPI_READ_SIZE);
172 
173 	ath25_add_wmac(0, AR2315_WLAN0_BASE, AR2315_IRQ_WLAN0);
174 }
175 
176 static void ar2315_restart(char *command)
177 {
178 	void (*mips_reset_vec)(void) = (void *)0xbfc00000;
179 
180 	local_irq_disable();
181 
182 	/* try reset the system via reset control */
183 	ar2315_rst_reg_write(AR2315_COLD_RESET, AR2317_RESET_SYSTEM);
184 
185 	/* Cold reset does not work on the AR2315/6, use the GPIO reset bits
186 	 * a workaround. Give it some time to attempt a gpio based hardware
187 	 * reset (atheros reference design workaround) */
188 
189 	/* TODO: implement the GPIO reset workaround */
190 
191 	/* Some boards (e.g. Senao EOC-2610) don't implement the reset logic
192 	 * workaround. Attempt to jump to the mips reset location -
193 	 * the boot loader itself might be able to recover the system */
194 	mips_reset_vec();
195 }
196 
197 /*
198  * This table is indexed by bits 5..4 of the CLOCKCTL1 register
199  * to determine the predevisor value.
200  */
201 static int clockctl1_predivide_table[4] __initdata = { 1, 2, 4, 5 };
202 static int pllc_divide_table[5] __initdata = { 2, 3, 4, 6, 3 };
203 
204 static unsigned __init ar2315_sys_clk(u32 clock_ctl)
205 {
206 	unsigned int pllc_ctrl, cpu_div;
207 	unsigned int pllc_out, refdiv, fdiv, divby2;
208 	unsigned int clk_div;
209 
210 	pllc_ctrl = ar2315_rst_reg_read(AR2315_PLLC_CTL);
211 	refdiv = ATH25_REG_MS(pllc_ctrl, AR2315_PLLC_REF_DIV);
212 	refdiv = clockctl1_predivide_table[refdiv];
213 	fdiv = ATH25_REG_MS(pllc_ctrl, AR2315_PLLC_FDBACK_DIV);
214 	divby2 = ATH25_REG_MS(pllc_ctrl, AR2315_PLLC_ADD_FDBACK_DIV) + 1;
215 	pllc_out = (40000000 / refdiv) * (2 * divby2) * fdiv;
216 
217 	/* clkm input selected */
218 	switch (clock_ctl & AR2315_CPUCLK_CLK_SEL_M) {
219 	case 0:
220 	case 1:
221 		clk_div = ATH25_REG_MS(pllc_ctrl, AR2315_PLLC_CLKM_DIV);
222 		clk_div = pllc_divide_table[clk_div];
223 		break;
224 	case 2:
225 		clk_div = ATH25_REG_MS(pllc_ctrl, AR2315_PLLC_CLKC_DIV);
226 		clk_div = pllc_divide_table[clk_div];
227 		break;
228 	default:
229 		pllc_out = 40000000;
230 		clk_div = 1;
231 		break;
232 	}
233 
234 	cpu_div = ATH25_REG_MS(clock_ctl, AR2315_CPUCLK_CLK_DIV);
235 	cpu_div = cpu_div * 2 ?: 1;
236 
237 	return pllc_out / (clk_div * cpu_div);
238 }
239 
240 static inline unsigned ar2315_cpu_frequency(void)
241 {
242 	return ar2315_sys_clk(ar2315_rst_reg_read(AR2315_CPUCLK));
243 }
244 
245 static inline unsigned ar2315_apb_frequency(void)
246 {
247 	return ar2315_sys_clk(ar2315_rst_reg_read(AR2315_AMBACLK));
248 }
249 
250 void __init ar2315_plat_time_init(void)
251 {
252 	mips_hpt_frequency = ar2315_cpu_frequency() / 2;
253 }
254 
255 void __init ar2315_plat_mem_setup(void)
256 {
257 	void __iomem *sdram_base;
258 	u32 memsize, memcfg;
259 	u32 devid;
260 	u32 config;
261 
262 	/* Detect memory size */
263 	sdram_base = ioremap(AR2315_SDRAMCTL_BASE,
264 				     AR2315_SDRAMCTL_SIZE);
265 	memcfg = __raw_readl(sdram_base + AR2315_MEM_CFG);
266 	memsize   = 1 + ATH25_REG_MS(memcfg, AR2315_MEM_CFG_DATA_WIDTH);
267 	memsize <<= 1 + ATH25_REG_MS(memcfg, AR2315_MEM_CFG_COL_WIDTH);
268 	memsize <<= 1 + ATH25_REG_MS(memcfg, AR2315_MEM_CFG_ROW_WIDTH);
269 	memsize <<= 3;
270 	memblock_add(0, memsize);
271 	iounmap(sdram_base);
272 
273 	ar2315_rst_base = ioremap(AR2315_RST_BASE, AR2315_RST_SIZE);
274 
275 	/* Detect the hardware based on the device ID */
276 	devid = ar2315_rst_reg_read(AR2315_SREV) & AR2315_REV_CHIP;
277 	switch (devid) {
278 	case 0x91:	/* Need to check */
279 		ath25_soc = ATH25_SOC_AR2318;
280 		break;
281 	case 0x90:
282 		ath25_soc = ATH25_SOC_AR2317;
283 		break;
284 	case 0x87:
285 		ath25_soc = ATH25_SOC_AR2316;
286 		break;
287 	case 0x86:
288 	default:
289 		ath25_soc = ATH25_SOC_AR2315;
290 		break;
291 	}
292 	ath25_board.devid = devid;
293 
294 	/* Clear any lingering AHB errors */
295 	config = read_c0_config();
296 	write_c0_config(config & ~0x3);
297 	ar2315_rst_reg_write(AR2315_AHB_ERR0, AR2315_AHB_ERROR_DET);
298 	ar2315_rst_reg_read(AR2315_AHB_ERR1);
299 	ar2315_rst_reg_write(AR2315_WDT_CTRL, AR2315_WDT_CTRL_IGNORE);
300 
301 	_machine_restart = ar2315_restart;
302 }
303 
304 #ifdef CONFIG_PCI_AR2315
305 static struct resource ar2315_pci_res[] = {
306 	{
307 		.name = "ar2315-pci-ctrl",
308 		.flags = IORESOURCE_MEM,
309 		.start = AR2315_PCI_BASE,
310 		.end = AR2315_PCI_BASE + AR2315_PCI_SIZE - 1,
311 	},
312 	{
313 		.name = "ar2315-pci-ext",
314 		.flags = IORESOURCE_MEM,
315 		.start = AR2315_PCI_EXT_BASE,
316 		.end = AR2315_PCI_EXT_BASE + AR2315_PCI_EXT_SIZE - 1,
317 	},
318 	{
319 		.name = "ar2315-pci",
320 		.flags = IORESOURCE_IRQ,
321 		.start = AR2315_IRQ_LCBUS_PCI,
322 		.end = AR2315_IRQ_LCBUS_PCI,
323 	},
324 };
325 #endif
326 
327 void __init ar2315_arch_init(void)
328 {
329 	unsigned irq = irq_create_mapping(ar2315_misc_irq_domain,
330 					  AR2315_MISC_IRQ_UART0);
331 
332 	ath25_serial_setup(AR2315_UART0_BASE, irq, ar2315_apb_frequency());
333 
334 #ifdef CONFIG_PCI_AR2315
335 	if (ath25_soc == ATH25_SOC_AR2315) {
336 		/* Reset PCI DMA logic */
337 		ar2315_rst_reg_mask(AR2315_RESET, 0, AR2315_RESET_PCIDMA);
338 		msleep(20);
339 		ar2315_rst_reg_mask(AR2315_RESET, AR2315_RESET_PCIDMA, 0);
340 		msleep(20);
341 
342 		/* Configure endians */
343 		ar2315_rst_reg_mask(AR2315_ENDIAN_CTL, 0, AR2315_CONFIG_PCIAHB |
344 				    AR2315_CONFIG_PCIAHB_BRIDGE);
345 
346 		/* Configure as PCI host with DMA */
347 		ar2315_rst_reg_write(AR2315_PCICLK, AR2315_PCICLK_PLLC_CLKM |
348 				  (AR2315_PCICLK_IN_FREQ_DIV_6 <<
349 				   AR2315_PCICLK_DIV_S));
350 		ar2315_rst_reg_mask(AR2315_AHB_ARB_CTL, 0, AR2315_ARB_PCI);
351 		ar2315_rst_reg_mask(AR2315_IF_CTL, AR2315_IF_PCI_CLK_MASK |
352 				    AR2315_IF_MASK, AR2315_IF_PCI |
353 				    AR2315_IF_PCI_HOST | AR2315_IF_PCI_INTR |
354 				    (AR2315_IF_PCI_CLK_OUTPUT_CLK <<
355 				     AR2315_IF_PCI_CLK_SHIFT));
356 
357 		platform_device_register_simple("ar2315-pci", -1,
358 						ar2315_pci_res,
359 						ARRAY_SIZE(ar2315_pci_res));
360 	}
361 #endif
362 }
363