1 // SPDX-License-Identifier: GPL-2.0-only
3  * Copyright (C) 2020 BAIKAL ELECTRONICS, JSC
8  * Baikal-T1 APB-bus driver
37  * struct bt1_apb - Baikal-T1 APB EHB private data
40  * @res: No-device error injection memory region.
42  * @rate: APB-bus reference clock rate.
43  * @pclk: APB-reference clock.
74 	do_div(timeout, apb->rate);  in bt1_apb_n_to_timeout_us()
83 	u64 n = (u64)timeout * apb->rate;  in bt1_apb_timeout_to_n_us()
96 	regmap_read(apb->regs, APB_EHB_ADDR, &addr);  in bt1_apb_isr()
98 	dev_crit_ratelimited(apb->dev,  in bt1_apb_isr()
99 		"APB-bus fault %d: Slave access timeout at 0x%08x\n",  in bt1_apb_isr()
100 		atomic_inc_return(&apb->count),  in bt1_apb_isr()
112 	regmap_update_bits(apb->regs, APB_EHB_ISR, APB_EHB_ISR_PENDING, 0);  in bt1_apb_isr()
120 	struct platform_device *pdev = to_platform_device(apb->dev);  in bt1_apb_clear_data()
127 	struct device *dev = &pdev->dev;  in bt1_apb_create_data()
133 		return ERR_PTR(-ENOMEM);  in bt1_apb_create_data()
141 	apb->dev = dev;  in bt1_apb_create_data()
142 	atomic_set(&apb->count, 0);  in bt1_apb_create_data()
150 	struct platform_device *pdev = to_platform_device(apb->dev);  in bt1_apb_request_regs()
155 		dev_err(apb->dev, "Couldn't map APB EHB registers\n");  in bt1_apb_request_regs()
159 	apb->regs = devm_regmap_init_mmio(apb->dev, regs, &bt1_apb_regmap_cfg);  in bt1_apb_request_regs()
160 	if (IS_ERR(apb->regs)) {  in bt1_apb_request_regs()
161 		dev_err(apb->dev, "Couldn't create APB EHB regmap\n");  in bt1_apb_request_regs()
162 		return PTR_ERR(apb->regs);  in bt1_apb_request_regs()
165 	apb->res = devm_platform_ioremap_resource_byname(pdev, "nodev");  in bt1_apb_request_regs()
166 	if (IS_ERR(apb->res))  in bt1_apb_request_regs()
167 		dev_err(apb->dev, "Couldn't map reserved region\n");  in bt1_apb_request_regs()
169 	return PTR_ERR_OR_ZERO(apb->res);  in bt1_apb_request_regs()
176 	apb->prst = devm_reset_control_get_optional_exclusive(apb->dev, "prst");  in bt1_apb_request_rst()
177 	if (IS_ERR(apb->prst))  in bt1_apb_request_rst()
178 		return dev_err_probe(apb->dev, PTR_ERR(apb->prst),  in bt1_apb_request_rst()
181 	ret = reset_control_deassert(apb->prst);  in bt1_apb_request_rst()
183 		dev_err(apb->dev, "Failed to deassert the reset line\n");  in bt1_apb_request_rst()
190 	apb->pclk = devm_clk_get_enabled(apb->dev, "pclk");  in bt1_apb_request_clk()
191 	if (IS_ERR(apb->pclk))  in bt1_apb_request_clk()
192 		return dev_err_probe(apb->dev, PTR_ERR(apb->pclk),  in bt1_apb_request_clk()
195 	apb->rate = clk_get_rate(apb->pclk);  in bt1_apb_request_clk()
196 	if (!apb->rate) {  in bt1_apb_request_clk()
197 		dev_err(apb->dev, "Invalid clock rate\n");  in bt1_apb_request_clk()
198 		return -EINVAL;  in bt1_apb_request_clk()
208 	regmap_update_bits(apb->regs, APB_EHB_ISR, APB_EHB_ISR_MASK, 0);  in bt1_apb_clear_irq()
213 	struct platform_device *pdev = to_platform_device(apb->dev);  in bt1_apb_request_irq()
216 	apb->irq = platform_get_irq(pdev, 0);  in bt1_apb_request_irq()
217 	if (apb->irq < 0)  in bt1_apb_request_irq()
218 		return apb->irq;  in bt1_apb_request_irq()
220 	ret = devm_request_irq(apb->dev, apb->irq, bt1_apb_isr, IRQF_SHARED,  in bt1_apb_request_irq()
221 			       "bt1-apb", apb);  in bt1_apb_request_irq()
223 		dev_err(apb->dev, "Couldn't request APB EHB IRQ\n");  in bt1_apb_request_irq()
227 	ret = devm_add_action(apb->dev, bt1_apb_clear_irq, apb);  in bt1_apb_request_irq()
229 		dev_err(apb->dev, "Can't add APB EHB IRQs clear action\n");  in bt1_apb_request_irq()
234 	regmap_update_bits(apb->regs, APB_EHB_ISR,  in bt1_apb_request_irq()
246 	return scnprintf(buf, PAGE_SIZE, "%d\n", atomic_read(&apb->count));  in count_show()
258 	ret = regmap_read(apb->regs, APB_EHB_TIMEOUT, &n);  in timeout_show()
277 		return -EINVAL;  in timeout_store()
282 	ret = regmap_write(apb->regs, APB_EHB_TIMEOUT, n);  in timeout_store()
305 		readl(apb->res);  in inject_error_store()
307 		regmap_update_bits(apb->regs, APB_EHB_ISR, APB_EHB_ISR_PENDING,  in inject_error_store()
310 		return -EINVAL;  in inject_error_store()
328 	device_remove_groups(apb->dev, bt1_apb_sysfs_groups);  in bt1_apb_remove_sysfs()
335 	ret = device_add_groups(apb->dev, bt1_apb_sysfs_groups);  in bt1_apb_init_sysfs()
337 		dev_err(apb->dev, "Failed to create EHB APB sysfs nodes\n");  in bt1_apb_init_sysfs()
341 	ret = devm_add_action_or_reset(apb->dev, bt1_apb_remove_sysfs, apb);  in bt1_apb_init_sysfs()
343 		dev_err(apb->dev, "Can't add APB EHB sysfs remove action\n");  in bt1_apb_init_sysfs()
381 	{ .compatible = "baikal,bt1-apb" },
389 		.name = "bt1-apb",
396 MODULE_DESCRIPTION("Baikal-T1 APB-bus driver");