1 // SPDX-License-Identifier: GPL-2.0-only
3  * Copyright (C) 2020 BAIKAL ELECTRONICS, JSC
8  * Baikal-T1 APB-bus driver
38  * struct bt1_apb - Baikal-T1 APB EHB private data
41  * @res: No-device error injection memory region.
43  * @rate: APB-bus reference clock rate.
44  * @pclk: APB-reference clock.
75 	do_div(timeout, apb->rate);  in bt1_apb_n_to_timeout_us()
84 	u64 n = (u64)timeout * apb->rate;  in bt1_apb_timeout_to_n_us()
97 	regmap_read(apb->regs, APB_EHB_ADDR, &addr);  in bt1_apb_isr()
99 	dev_crit_ratelimited(apb->dev,  in bt1_apb_isr()
100 		"APB-bus fault %d: Slave access timeout at 0x%08x\n",  in bt1_apb_isr()
101 		atomic_inc_return(&apb->count),  in bt1_apb_isr()
113 	regmap_update_bits(apb->regs, APB_EHB_ISR, APB_EHB_ISR_PENDING, 0);  in bt1_apb_isr()
121 	struct platform_device *pdev = to_platform_device(apb->dev);  in bt1_apb_clear_data()
128 	struct device *dev = &pdev->dev;  in bt1_apb_create_data()
134 		return ERR_PTR(-ENOMEM);  in bt1_apb_create_data()
142 	apb->dev = dev;  in bt1_apb_create_data()
143 	atomic_set(&apb->count, 0);  in bt1_apb_create_data()
151 	struct platform_device *pdev = to_platform_device(apb->dev);  in bt1_apb_request_regs()
156 		dev_err(apb->dev, "Couldn't map APB EHB registers\n");  in bt1_apb_request_regs()
160 	apb->regs = devm_regmap_init_mmio(apb->dev, regs, &bt1_apb_regmap_cfg);  in bt1_apb_request_regs()
161 	if (IS_ERR(apb->regs)) {  in bt1_apb_request_regs()
162 		dev_err(apb->dev, "Couldn't create APB EHB regmap\n");  in bt1_apb_request_regs()
163 		return PTR_ERR(apb->regs);  in bt1_apb_request_regs()
166 	apb->res = devm_platform_ioremap_resource_byname(pdev, "nodev");  in bt1_apb_request_regs()
167 	if (IS_ERR(apb->res))  in bt1_apb_request_regs()
168 		dev_err(apb->dev, "Couldn't map reserved region\n");  in bt1_apb_request_regs()
170 	return PTR_ERR_OR_ZERO(apb->res);  in bt1_apb_request_regs()
177 	apb->prst = devm_reset_control_get_optional_exclusive(apb->dev, "prst");  in bt1_apb_request_rst()
178 	if (IS_ERR(apb->prst)) {  in bt1_apb_request_rst()
179 		dev_warn(apb->dev, "Couldn't get reset control line\n");  in bt1_apb_request_rst()
180 		return PTR_ERR(apb->prst);  in bt1_apb_request_rst()
183 	ret = reset_control_deassert(apb->prst);  in bt1_apb_request_rst()
185 		dev_err(apb->dev, "Failed to deassert the reset line\n");  in bt1_apb_request_rst()
194 	clk_disable_unprepare(apb->pclk);  in bt1_apb_disable_clk()
201 	apb->pclk = devm_clk_get(apb->dev, "pclk");  in bt1_apb_request_clk()
202 	if (IS_ERR(apb->pclk)) {  in bt1_apb_request_clk()
203 		dev_err(apb->dev, "Couldn't get APB clock descriptor\n");  in bt1_apb_request_clk()
204 		return PTR_ERR(apb->pclk);  in bt1_apb_request_clk()
207 	ret = clk_prepare_enable(apb->pclk);  in bt1_apb_request_clk()
209 		dev_err(apb->dev, "Couldn't enable the APB clock\n");  in bt1_apb_request_clk()
213 	ret = devm_add_action_or_reset(apb->dev, bt1_apb_disable_clk, apb);  in bt1_apb_request_clk()
215 		dev_err(apb->dev, "Can't add APB EHB clocks disable action\n");  in bt1_apb_request_clk()
219 	apb->rate = clk_get_rate(apb->pclk);  in bt1_apb_request_clk()
220 	if (!apb->rate) {  in bt1_apb_request_clk()
221 		dev_err(apb->dev, "Invalid clock rate\n");  in bt1_apb_request_clk()
222 		return -EINVAL;  in bt1_apb_request_clk()
232 	regmap_update_bits(apb->regs, APB_EHB_ISR, APB_EHB_ISR_MASK, 0);  in bt1_apb_clear_irq()
237 	struct platform_device *pdev = to_platform_device(apb->dev);  in bt1_apb_request_irq()
240 	apb->irq = platform_get_irq(pdev, 0);  in bt1_apb_request_irq()
241 	if (apb->irq < 0)  in bt1_apb_request_irq()
242 		return apb->irq;  in bt1_apb_request_irq()
244 	ret = devm_request_irq(apb->dev, apb->irq, bt1_apb_isr, IRQF_SHARED,  in bt1_apb_request_irq()
245 			       "bt1-apb", apb);  in bt1_apb_request_irq()
247 		dev_err(apb->dev, "Couldn't request APB EHB IRQ\n");  in bt1_apb_request_irq()
251 	ret = devm_add_action(apb->dev, bt1_apb_clear_irq, apb);  in bt1_apb_request_irq()
253 		dev_err(apb->dev, "Can't add APB EHB IRQs clear action\n");  in bt1_apb_request_irq()
258 	regmap_update_bits(apb->regs, APB_EHB_ISR,  in bt1_apb_request_irq()
270 	return scnprintf(buf, PAGE_SIZE, "%d\n", atomic_read(&apb->count));  in count_show()
282 	ret = regmap_read(apb->regs, APB_EHB_TIMEOUT, &n);  in timeout_show()
301 		return -EINVAL;  in timeout_store()
306 	ret = regmap_write(apb->regs, APB_EHB_TIMEOUT, n);  in timeout_store()
329 		readl(apb->res);  in inject_error_store()
331 		regmap_update_bits(apb->regs, APB_EHB_ISR, APB_EHB_ISR_PENDING,  in inject_error_store()
334 		return -EINVAL;  in inject_error_store()
352 	device_remove_groups(apb->dev, bt1_apb_sysfs_groups);  in bt1_apb_remove_sysfs()
359 	ret = device_add_groups(apb->dev, bt1_apb_sysfs_groups);  in bt1_apb_init_sysfs()
361 		dev_err(apb->dev, "Failed to create EHB APB sysfs nodes\n");  in bt1_apb_init_sysfs()
365 	ret = devm_add_action_or_reset(apb->dev, bt1_apb_remove_sysfs, apb);  in bt1_apb_init_sysfs()
367 		dev_err(apb->dev, "Can't add APB EHB sysfs remove action\n");  in bt1_apb_init_sysfs()
405 	{ .compatible = "baikal,bt1-apb" },
413 		.name = "bt1-apb",
420 MODULE_DESCRIPTION("Baikal-T1 APB-bus driver");