1 // SPDX-License-Identifier: GPL-2.0
6  * Samsung Exynos USI driver (Universal Serial Interface).
17 #include <dt-bindings/soc/samsung,exynos-usi.h>
27 /* USIv2: USI register offsets */
31 /* USIv2: USI register bits */
41 	enum exynos_usi_ver ver;	/* USI IP-core version */
51 	void __iomem *regs;		/* USI register map */
52 	struct clk_bulk_data *clks;	/* USI clocks */
54 	size_t mode;			/* current USI SW_CONF mode index */
88 		.compatible = "samsung,exynos850-usi",
96  * exynos_usi_set_sw_conf - Set USI block configuration mode
97  * @usi: USI driver object
100  * Select underlying serial protocol (UART/SPI/I2C) in USI IP-core.
104 static int exynos_usi_set_sw_conf(struct exynos_usi *usi, size_t mode)  in exynos_usi_set_sw_conf()  argument
109 	if (mode < usi->data->min_mode || mode > usi->data->max_mode)  in exynos_usi_set_sw_conf()
110 		return -EINVAL;  in exynos_usi_set_sw_conf()
113 	ret = regmap_update_bits(usi->sysreg, usi->sw_conf,  in exynos_usi_set_sw_conf()
114 				 usi->data->sw_conf_mask, val);  in exynos_usi_set_sw_conf()
118 	usi->mode = mode;  in exynos_usi_set_sw_conf()
119 	dev_dbg(usi->dev, "protocol: %s\n", exynos_usi_modes[usi->mode].name);  in exynos_usi_set_sw_conf()
125  * exynos_usi_enable - Initialize USI block
126  * @usi: USI driver object
128  * USI IP-core start state is "reset" (on startup and after CPU resume). This
129  * routine enables the USI block by clearing the reset flag. It also configures
135 static int exynos_usi_enable(const struct exynos_usi *usi)  in exynos_usi_enable()  argument
140 	ret = clk_bulk_prepare_enable(usi->data->num_clks, usi->clks);  in exynos_usi_enable()
144 	/* Enable USI block */  in exynos_usi_enable()
145 	val = readl(usi->regs + USI_CON);  in exynos_usi_enable()
147 	writel(val, usi->regs + USI_CON);  in exynos_usi_enable()
150 	/* Continuously provide the clock to USI IP w/o gating */  in exynos_usi_enable()
151 	if (usi->clkreq_on) {  in exynos_usi_enable()
152 		val = readl(usi->regs + USI_OPTION);  in exynos_usi_enable()
155 		writel(val, usi->regs + USI_OPTION);  in exynos_usi_enable()
158 	clk_bulk_disable_unprepare(usi->data->num_clks, usi->clks);  in exynos_usi_enable()
163 static int exynos_usi_configure(struct exynos_usi *usi)  in exynos_usi_configure()  argument
167 	ret = exynos_usi_set_sw_conf(usi, usi->mode);  in exynos_usi_configure()
171 	if (usi->data->ver == USI_VER2)  in exynos_usi_configure()
172 		return exynos_usi_enable(usi);  in exynos_usi_configure()
177 static int exynos_usi_parse_dt(struct device_node *np, struct exynos_usi *usi)  in exynos_usi_parse_dt()  argument
185 	if (mode < usi->data->min_mode || mode > usi->data->max_mode)  in exynos_usi_parse_dt()
186 		return -EINVAL;  in exynos_usi_parse_dt()
187 	usi->mode = mode;  in exynos_usi_parse_dt()
189 	usi->sysreg = syscon_regmap_lookup_by_phandle(np, "samsung,sysreg");  in exynos_usi_parse_dt()
190 	if (IS_ERR(usi->sysreg))  in exynos_usi_parse_dt()
191 		return PTR_ERR(usi->sysreg);  in exynos_usi_parse_dt()
194 					 &usi->sw_conf);  in exynos_usi_parse_dt()
198 	usi->clkreq_on = of_property_read_bool(np, "samsung,clkreq-on");  in exynos_usi_parse_dt()
203 static int exynos_usi_get_clocks(struct exynos_usi *usi)  in exynos_usi_get_clocks()  argument
205 	const size_t num = usi->data->num_clks;  in exynos_usi_get_clocks()
206 	struct device *dev = usi->dev;  in exynos_usi_get_clocks()
212 	usi->clks = devm_kcalloc(dev, num, sizeof(*usi->clks), GFP_KERNEL);  in exynos_usi_get_clocks()
213 	if (!usi->clks)  in exynos_usi_get_clocks()
214 		return -ENOMEM;  in exynos_usi_get_clocks()
217 		usi->clks[i].id = usi->data->clk_names[i];  in exynos_usi_get_clocks()
219 	return devm_clk_bulk_get(dev, num, usi->clks);  in exynos_usi_get_clocks()
224 	struct device *dev = &pdev->dev;  in exynos_usi_probe()
225 	struct device_node *np = dev->of_node;  in exynos_usi_probe()
226 	struct exynos_usi *usi;  in exynos_usi_probe()  local
229 	usi = devm_kzalloc(dev, sizeof(*usi), GFP_KERNEL);  in exynos_usi_probe()
230 	if (!usi)  in exynos_usi_probe()
231 		return -ENOMEM;  in exynos_usi_probe()
233 	usi->dev = dev;  in exynos_usi_probe()
234 	platform_set_drvdata(pdev, usi);  in exynos_usi_probe()
236 	usi->data = of_device_get_match_data(dev);  in exynos_usi_probe()
237 	if (!usi->data)  in exynos_usi_probe()
238 		return -EINVAL;  in exynos_usi_probe()
240 	ret = exynos_usi_parse_dt(np, usi);  in exynos_usi_probe()
244 	ret = exynos_usi_get_clocks(usi);  in exynos_usi_probe()
248 	if (usi->data->ver == USI_VER2) {  in exynos_usi_probe()
249 		usi->regs = devm_platform_ioremap_resource(pdev, 0);  in exynos_usi_probe()
250 		if (IS_ERR(usi->regs))  in exynos_usi_probe()
251 			return PTR_ERR(usi->regs);  in exynos_usi_probe()
254 	ret = exynos_usi_configure(usi);  in exynos_usi_probe()
258 	/* Make it possible to embed protocol nodes into USI np */  in exynos_usi_probe()
264 	struct exynos_usi *usi = dev_get_drvdata(dev);  in exynos_usi_resume_noirq()  local
266 	return exynos_usi_configure(usi);  in exynos_usi_resume_noirq()
275 		.name		= "exynos-usi",
283 MODULE_DESCRIPTION("Samsung USI driver");