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  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
 35static void __iomem *ar2315_rst_base;
 36static struct irq_domain *ar2315_misc_irq_domain;
 37
 38static inline u32 ar2315_rst_reg_read(u32 reg)
 39{
 40	return __raw_readl(ar2315_rst_base + reg);
 41}
 42
 43static inline void ar2315_rst_reg_write(u32 reg, u32 val)
 44{
 45	__raw_writel(val, ar2315_rst_base + reg);
 46}
 47
 48static 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
 57static 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
 68static 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;
 73	int ret = 0;
 74
 75	if (pending) {
 76		struct irq_domain *domain = irq_desc_get_handler_data(desc);
 77
 78		nr = __ffs(pending);
 79
 80		if (nr == AR2315_MISC_IRQ_GPIO)
 81			ar2315_rst_reg_write(AR2315_ISR, AR2315_ISR_GPIO);
 82		else if (nr == AR2315_MISC_IRQ_WATCHDOG)
 83			ar2315_rst_reg_write(AR2315_ISR, AR2315_ISR_WD);
 84
 85		ret = generic_handle_domain_irq(domain, nr);
 86	}
 87
 88	if (!pending || ret)
 89		spurious_interrupt();
 90}
 91
 92static void ar2315_misc_irq_unmask(struct irq_data *d)
 93{
 94	ar2315_rst_reg_mask(AR2315_IMR, 0, BIT(d->hwirq));
 95}
 96
 97static void ar2315_misc_irq_mask(struct irq_data *d)
 98{
 99	ar2315_rst_reg_mask(AR2315_IMR, BIT(d->hwirq), 0);
100}
101
102static 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
108static 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
115static const 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 */
127static 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
145void __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
168void __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
176static 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 */
201static int clockctl1_predivide_table[4] __initdata = { 1, 2, 4, 5 };
202static int pllc_divide_table[5] __initdata = { 2, 3, 4, 6, 3 };
203
204static 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
240static inline unsigned ar2315_cpu_frequency(void)
241{
242	return ar2315_sys_clk(ar2315_rst_reg_read(AR2315_CPUCLK));
243}
244
245static inline unsigned ar2315_apb_frequency(void)
246{
247	return ar2315_sys_clk(ar2315_rst_reg_read(AR2315_AMBACLK));
248}
249
250void __init ar2315_plat_time_init(void)
251{
252	mips_hpt_frequency = ar2315_cpu_frequency() / 2;
253}
254
255void __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
305static 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
327void __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}