1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Driver for the MMC / SD / SDIO cell found in:
4  *
5  * TC6393XB TC6391XB TC6387XB T7L66XB ASIC3
6  *
7  * Copyright (C) 2017 Renesas Electronics Corporation
8  * Copyright (C) 2017 Horms Solutions, Simon Horman
9  * Copyright (C) 2007 Ian Molton
10  * Copyright (C) 2004 Ian Molton
11  */
12 
13 #include <linux/delay.h>
14 #include <linux/device.h>
15 #include <linux/mfd/core.h>
16 #include <linux/mfd/tmio.h>
17 #include <linux/mmc/host.h>
18 #include <linux/module.h>
19 #include <linux/pagemap.h>
20 #include <linux/scatterlist.h>
21 
22 #include "tmio_mmc.h"
23 
24 /* Registers specific to this variant */
25 #define CTL_SDIO_REGS		0x100
26 #define CTL_CLK_AND_WAIT_CTL	0x138
27 #define CTL_RESET_SDIO		0x1e0
28 
tmio_mmc_clk_start(struct tmio_mmc_host * host)29 static void tmio_mmc_clk_start(struct tmio_mmc_host *host)
30 {
31 	sd_ctrl_write16(host, CTL_SD_CARD_CLK_CTL, CLK_CTL_SCLKEN |
32 		sd_ctrl_read16(host, CTL_SD_CARD_CLK_CTL));
33 
34 	usleep_range(10000, 11000);
35 	sd_ctrl_write16(host, CTL_CLK_AND_WAIT_CTL, 0x0100);
36 	usleep_range(10000, 11000);
37 }
38 
tmio_mmc_clk_stop(struct tmio_mmc_host * host)39 static void tmio_mmc_clk_stop(struct tmio_mmc_host *host)
40 {
41 	sd_ctrl_write16(host, CTL_CLK_AND_WAIT_CTL, 0x0000);
42 	usleep_range(10000, 11000);
43 
44 	sd_ctrl_write16(host, CTL_SD_CARD_CLK_CTL, ~CLK_CTL_SCLKEN &
45 		sd_ctrl_read16(host, CTL_SD_CARD_CLK_CTL));
46 
47 	usleep_range(10000, 11000);
48 }
49 
tmio_mmc_set_clock(struct tmio_mmc_host * host,unsigned int new_clock)50 static void tmio_mmc_set_clock(struct tmio_mmc_host *host,
51 			       unsigned int new_clock)
52 {
53 	unsigned int divisor;
54 	u32 clk = 0;
55 	int clk_sel;
56 
57 	if (new_clock == 0) {
58 		tmio_mmc_clk_stop(host);
59 		return;
60 	}
61 
62 	divisor = host->pdata->hclk / new_clock;
63 
64 	/* bit7 set: 1/512, ... bit0 set: 1/4, all bits clear: 1/2 */
65 	clk_sel = (divisor <= 1);
66 	clk = clk_sel ? 0 : (roundup_pow_of_two(divisor) >> 2);
67 
68 	host->pdata->set_clk_div(host->pdev, clk_sel);
69 
70 	sd_ctrl_write16(host, CTL_SD_CARD_CLK_CTL, ~CLK_CTL_SCLKEN &
71 			sd_ctrl_read16(host, CTL_SD_CARD_CLK_CTL));
72 	sd_ctrl_write16(host, CTL_SD_CARD_CLK_CTL, clk & CLK_CTL_DIV_MASK);
73 	usleep_range(10000, 11000);
74 
75 	tmio_mmc_clk_start(host);
76 }
77 
tmio_mmc_reset(struct tmio_mmc_host * host)78 static void tmio_mmc_reset(struct tmio_mmc_host *host)
79 {
80 	sd_ctrl_write16(host, CTL_RESET_SDIO, 0x0000);
81 	usleep_range(10000, 11000);
82 	sd_ctrl_write16(host, CTL_RESET_SDIO, 0x0001);
83 	usleep_range(10000, 11000);
84 }
85 
86 #ifdef CONFIG_PM_SLEEP
tmio_mmc_suspend(struct device * dev)87 static int tmio_mmc_suspend(struct device *dev)
88 {
89 	struct platform_device *pdev = to_platform_device(dev);
90 	const struct mfd_cell *cell = mfd_get_cell(pdev);
91 	int ret;
92 
93 	ret = pm_runtime_force_suspend(dev);
94 
95 	/* Tell MFD core it can disable us now.*/
96 	if (!ret && cell->disable)
97 		cell->disable(pdev);
98 
99 	return ret;
100 }
101 
tmio_mmc_resume(struct device * dev)102 static int tmio_mmc_resume(struct device *dev)
103 {
104 	struct platform_device *pdev = to_platform_device(dev);
105 	const struct mfd_cell *cell = mfd_get_cell(pdev);
106 	int ret = 0;
107 
108 	/* Tell the MFD core we are ready to be enabled */
109 	if (cell->resume)
110 		ret = cell->resume(pdev);
111 
112 	if (!ret)
113 		ret = pm_runtime_force_resume(dev);
114 
115 	return ret;
116 }
117 #endif
118 
tmio_mmc_probe(struct platform_device * pdev)119 static int tmio_mmc_probe(struct platform_device *pdev)
120 {
121 	const struct mfd_cell *cell = mfd_get_cell(pdev);
122 	struct tmio_mmc_data *pdata;
123 	struct tmio_mmc_host *host;
124 	struct resource *res;
125 	int ret = -EINVAL, irq;
126 
127 	if (pdev->num_resources != 2)
128 		goto out;
129 
130 	pdata = pdev->dev.platform_data;
131 	if (!pdata || !pdata->hclk)
132 		goto out;
133 
134 	irq = platform_get_irq(pdev, 0);
135 	if (irq < 0) {
136 		ret = irq;
137 		goto out;
138 	}
139 
140 	/* Tell the MFD core we are ready to be enabled */
141 	if (cell->enable) {
142 		ret = cell->enable(pdev);
143 		if (ret)
144 			goto out;
145 	}
146 
147 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
148 	if (!res) {
149 		ret = -EINVAL;
150 		goto cell_disable;
151 	}
152 
153 	host = tmio_mmc_host_alloc(pdev, pdata);
154 	if (IS_ERR(host)) {
155 		ret = PTR_ERR(host);
156 		goto cell_disable;
157 	}
158 
159 	/* SD control register space size is 0x200, 0x400 for bus_shift=1 */
160 	host->bus_shift = resource_size(res) >> 10;
161 	host->set_clock = tmio_mmc_set_clock;
162 	host->reset = tmio_mmc_reset;
163 
164 	host->mmc->f_max = pdata->hclk;
165 	host->mmc->f_min = pdata->hclk / 512;
166 
167 	ret = tmio_mmc_host_probe(host);
168 	if (ret)
169 		goto host_free;
170 
171 	ret = devm_request_irq(&pdev->dev, irq, tmio_mmc_irq,
172 			       IRQF_TRIGGER_FALLING,
173 			       dev_name(&pdev->dev), host);
174 	if (ret)
175 		goto host_remove;
176 
177 	pr_info("%s at 0x%p irq %d\n", mmc_hostname(host->mmc), host->ctl, irq);
178 
179 	return 0;
180 
181 host_remove:
182 	tmio_mmc_host_remove(host);
183 host_free:
184 	tmio_mmc_host_free(host);
185 cell_disable:
186 	if (cell->disable)
187 		cell->disable(pdev);
188 out:
189 	return ret;
190 }
191 
tmio_mmc_remove(struct platform_device * pdev)192 static int tmio_mmc_remove(struct platform_device *pdev)
193 {
194 	const struct mfd_cell *cell = mfd_get_cell(pdev);
195 	struct tmio_mmc_host *host = platform_get_drvdata(pdev);
196 
197 	tmio_mmc_host_remove(host);
198 	if (cell->disable)
199 		cell->disable(pdev);
200 
201 	return 0;
202 }
203 
204 /* ------------------- device registration ----------------------- */
205 
206 static const struct dev_pm_ops tmio_mmc_dev_pm_ops = {
207 	SET_SYSTEM_SLEEP_PM_OPS(tmio_mmc_suspend, tmio_mmc_resume)
208 	SET_RUNTIME_PM_OPS(tmio_mmc_host_runtime_suspend,
209 			   tmio_mmc_host_runtime_resume, NULL)
210 };
211 
212 static struct platform_driver tmio_mmc_driver = {
213 	.driver = {
214 		.name = "tmio-mmc",
215 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
216 		.pm = &tmio_mmc_dev_pm_ops,
217 	},
218 	.probe = tmio_mmc_probe,
219 	.remove = tmio_mmc_remove,
220 };
221 
222 module_platform_driver(tmio_mmc_driver);
223 
224 MODULE_DESCRIPTION("Toshiba TMIO SD/MMC driver");
225 MODULE_AUTHOR("Ian Molton <spyro@f2s.com>");
226 MODULE_LICENSE("GPL v2");
227 MODULE_ALIAS("platform:tmio-mmc");
228