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1/*
2 * CLPS711X SPI bus driver
3 *
4 * Copyright (C) 2012-2016 Alexander Shiyan <shc_work@mail.ru>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 */
11
12#include <linux/io.h>
13#include <linux/clk.h>
14#include <linux/gpio.h>
15#include <linux/module.h>
16#include <linux/interrupt.h>
17#include <linux/platform_device.h>
18#include <linux/regmap.h>
19#include <linux/mfd/syscon.h>
20#include <linux/mfd/syscon/clps711x.h>
21#include <linux/spi/spi.h>
22
23#define DRIVER_NAME "clps711x-spi"
24
25#define SYNCIO_FRMLEN(x) ((x) << 8)
26#define SYNCIO_TXFRMEN (1 << 14)
27
28struct spi_clps711x_data {
29 void __iomem *syncio;
30 struct regmap *syscon;
31 struct clk *spi_clk;
32
33 u8 *tx_buf;
34 u8 *rx_buf;
35 unsigned int bpw;
36 int len;
37};
38
39static int spi_clps711x_setup(struct spi_device *spi)
40{
41 if (!spi->controller_state) {
42 int ret;
43
44 ret = devm_gpio_request(&spi->master->dev, spi->cs_gpio,
45 dev_name(&spi->master->dev));
46 if (ret)
47 return ret;
48
49 spi->controller_state = spi;
50 }
51
52 /* We are expect that SPI-device is not selected */
53 gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
54
55 return 0;
56}
57
58static int spi_clps711x_prepare_message(struct spi_master *master,
59 struct spi_message *msg)
60{
61 struct spi_clps711x_data *hw = spi_master_get_devdata(master);
62 struct spi_device *spi = msg->spi;
63
64 /* Setup mode for transfer */
65 return regmap_update_bits(hw->syscon, SYSCON_OFFSET, SYSCON3_ADCCKNSEN,
66 (spi->mode & SPI_CPHA) ?
67 SYSCON3_ADCCKNSEN : 0);
68}
69
70static int spi_clps711x_transfer_one(struct spi_master *master,
71 struct spi_device *spi,
72 struct spi_transfer *xfer)
73{
74 struct spi_clps711x_data *hw = spi_master_get_devdata(master);
75 u8 data;
76
77 clk_set_rate(hw->spi_clk, xfer->speed_hz ? : spi->max_speed_hz);
78
79 hw->len = xfer->len;
80 hw->bpw = xfer->bits_per_word;
81 hw->tx_buf = (u8 *)xfer->tx_buf;
82 hw->rx_buf = (u8 *)xfer->rx_buf;
83
84 /* Initiate transfer */
85 data = hw->tx_buf ? *hw->tx_buf++ : 0;
86 writel(data | SYNCIO_FRMLEN(hw->bpw) | SYNCIO_TXFRMEN, hw->syncio);
87
88 return 1;
89}
90
91static irqreturn_t spi_clps711x_isr(int irq, void *dev_id)
92{
93 struct spi_master *master = dev_id;
94 struct spi_clps711x_data *hw = spi_master_get_devdata(master);
95 u8 data;
96
97 /* Handle RX */
98 data = readb(hw->syncio);
99 if (hw->rx_buf)
100 *hw->rx_buf++ = data;
101
102 /* Handle TX */
103 if (--hw->len > 0) {
104 data = hw->tx_buf ? *hw->tx_buf++ : 0;
105 writel(data | SYNCIO_FRMLEN(hw->bpw) | SYNCIO_TXFRMEN,
106 hw->syncio);
107 } else
108 spi_finalize_current_transfer(master);
109
110 return IRQ_HANDLED;
111}
112
113static int spi_clps711x_probe(struct platform_device *pdev)
114{
115 struct spi_clps711x_data *hw;
116 struct spi_master *master;
117 struct resource *res;
118 int irq, ret;
119
120 irq = platform_get_irq(pdev, 0);
121 if (irq < 0)
122 return irq;
123
124 master = spi_alloc_master(&pdev->dev, sizeof(*hw));
125 if (!master)
126 return -ENOMEM;
127
128 master->bus_num = -1;
129 master->mode_bits = SPI_CPHA | SPI_CS_HIGH;
130 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 8);
131 master->dev.of_node = pdev->dev.of_node;
132 master->setup = spi_clps711x_setup;
133 master->prepare_message = spi_clps711x_prepare_message;
134 master->transfer_one = spi_clps711x_transfer_one;
135
136 hw = spi_master_get_devdata(master);
137
138 hw->spi_clk = devm_clk_get(&pdev->dev, NULL);
139 if (IS_ERR(hw->spi_clk)) {
140 ret = PTR_ERR(hw->spi_clk);
141 goto err_out;
142 }
143
144 hw->syscon =
145 syscon_regmap_lookup_by_compatible("cirrus,ep7209-syscon3");
146 if (IS_ERR(hw->syscon)) {
147 ret = PTR_ERR(hw->syscon);
148 goto err_out;
149 }
150
151 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
152 hw->syncio = devm_ioremap_resource(&pdev->dev, res);
153 if (IS_ERR(hw->syncio)) {
154 ret = PTR_ERR(hw->syncio);
155 goto err_out;
156 }
157
158 /* Disable extended mode due hardware problems */
159 regmap_update_bits(hw->syscon, SYSCON_OFFSET, SYSCON3_ADCCON, 0);
160
161 /* Clear possible pending interrupt */
162 readl(hw->syncio);
163
164 ret = devm_request_irq(&pdev->dev, irq, spi_clps711x_isr, 0,
165 dev_name(&pdev->dev), master);
166 if (ret)
167 goto err_out;
168
169 ret = devm_spi_register_master(&pdev->dev, master);
170 if (!ret)
171 return 0;
172
173err_out:
174 spi_master_put(master);
175
176 return ret;
177}
178
179static const struct of_device_id clps711x_spi_dt_ids[] = {
180 { .compatible = "cirrus,ep7209-spi", },
181 { }
182};
183MODULE_DEVICE_TABLE(of, clps711x_spi_dt_ids);
184
185static struct platform_driver clps711x_spi_driver = {
186 .driver = {
187 .name = DRIVER_NAME,
188 .of_match_table = clps711x_spi_dt_ids,
189 },
190 .probe = spi_clps711x_probe,
191};
192module_platform_driver(clps711x_spi_driver);
193
194MODULE_LICENSE("GPL");
195MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
196MODULE_DESCRIPTION("CLPS711X SPI bus driver");
197MODULE_ALIAS("platform:" DRIVER_NAME);
1/*
2 * CLPS711X SPI bus driver
3 *
4 * Copyright (C) 2012-2014 Alexander Shiyan <shc_work@mail.ru>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 */
11
12#include <linux/io.h>
13#include <linux/clk.h>
14#include <linux/gpio.h>
15#include <linux/delay.h>
16#include <linux/module.h>
17#include <linux/interrupt.h>
18#include <linux/platform_device.h>
19#include <linux/regmap.h>
20#include <linux/mfd/syscon.h>
21#include <linux/mfd/syscon/clps711x.h>
22#include <linux/spi/spi.h>
23#include <linux/platform_data/spi-clps711x.h>
24
25#define DRIVER_NAME "spi-clps711x"
26
27#define SYNCIO_FRMLEN(x) ((x) << 8)
28#define SYNCIO_TXFRMEN (1 << 14)
29
30struct spi_clps711x_data {
31 void __iomem *syncio;
32 struct regmap *syscon;
33 struct clk *spi_clk;
34
35 u8 *tx_buf;
36 u8 *rx_buf;
37 unsigned int bpw;
38 int len;
39};
40
41static int spi_clps711x_setup(struct spi_device *spi)
42{
43 /* We are expect that SPI-device is not selected */
44 gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
45
46 return 0;
47}
48
49static int spi_clps711x_prepare_message(struct spi_master *master,
50 struct spi_message *msg)
51{
52 struct spi_clps711x_data *hw = spi_master_get_devdata(master);
53 struct spi_device *spi = msg->spi;
54
55 /* Setup mode for transfer */
56 return regmap_update_bits(hw->syscon, SYSCON_OFFSET, SYSCON3_ADCCKNSEN,
57 (spi->mode & SPI_CPHA) ?
58 SYSCON3_ADCCKNSEN : 0);
59}
60
61static int spi_clps711x_transfer_one(struct spi_master *master,
62 struct spi_device *spi,
63 struct spi_transfer *xfer)
64{
65 struct spi_clps711x_data *hw = spi_master_get_devdata(master);
66 u8 data;
67
68 clk_set_rate(hw->spi_clk, xfer->speed_hz ? : spi->max_speed_hz);
69
70 hw->len = xfer->len;
71 hw->bpw = xfer->bits_per_word;
72 hw->tx_buf = (u8 *)xfer->tx_buf;
73 hw->rx_buf = (u8 *)xfer->rx_buf;
74
75 /* Initiate transfer */
76 data = hw->tx_buf ? *hw->tx_buf++ : 0;
77 writel(data | SYNCIO_FRMLEN(hw->bpw) | SYNCIO_TXFRMEN, hw->syncio);
78
79 return 1;
80}
81
82static irqreturn_t spi_clps711x_isr(int irq, void *dev_id)
83{
84 struct spi_master *master = dev_id;
85 struct spi_clps711x_data *hw = spi_master_get_devdata(master);
86 u8 data;
87
88 /* Handle RX */
89 data = readb(hw->syncio);
90 if (hw->rx_buf)
91 *hw->rx_buf++ = data;
92
93 /* Handle TX */
94 if (--hw->len > 0) {
95 data = hw->tx_buf ? *hw->tx_buf++ : 0;
96 writel(data | SYNCIO_FRMLEN(hw->bpw) | SYNCIO_TXFRMEN,
97 hw->syncio);
98 } else
99 spi_finalize_current_transfer(master);
100
101 return IRQ_HANDLED;
102}
103
104static int spi_clps711x_probe(struct platform_device *pdev)
105{
106 struct spi_clps711x_data *hw;
107 struct spi_clps711x_pdata *pdata = dev_get_platdata(&pdev->dev);
108 struct spi_master *master;
109 struct resource *res;
110 int i, irq, ret;
111
112 if (!pdata) {
113 dev_err(&pdev->dev, "No platform data supplied\n");
114 return -EINVAL;
115 }
116
117 if (pdata->num_chipselect < 1) {
118 dev_err(&pdev->dev, "At least one CS must be defined\n");
119 return -EINVAL;
120 }
121
122 irq = platform_get_irq(pdev, 0);
123 if (irq < 0)
124 return irq;
125
126 master = spi_alloc_master(&pdev->dev, sizeof(*hw));
127 if (!master)
128 return -ENOMEM;
129
130 master->cs_gpios = devm_kzalloc(&pdev->dev, sizeof(int) *
131 pdata->num_chipselect, GFP_KERNEL);
132 if (!master->cs_gpios) {
133 ret = -ENOMEM;
134 goto err_out;
135 }
136
137 master->bus_num = pdev->id;
138 master->mode_bits = SPI_CPHA | SPI_CS_HIGH;
139 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 8);
140 master->num_chipselect = pdata->num_chipselect;
141 master->setup = spi_clps711x_setup;
142 master->prepare_message = spi_clps711x_prepare_message;
143 master->transfer_one = spi_clps711x_transfer_one;
144
145 hw = spi_master_get_devdata(master);
146
147 for (i = 0; i < master->num_chipselect; i++) {
148 master->cs_gpios[i] = pdata->chipselect[i];
149 ret = devm_gpio_request(&pdev->dev, master->cs_gpios[i],
150 DRIVER_NAME);
151 if (ret) {
152 dev_err(&pdev->dev, "Can't get CS GPIO %i\n", i);
153 goto err_out;
154 }
155 }
156
157 hw->spi_clk = devm_clk_get(&pdev->dev, NULL);
158 if (IS_ERR(hw->spi_clk)) {
159 ret = PTR_ERR(hw->spi_clk);
160 goto err_out;
161 }
162
163 hw->syscon = syscon_regmap_lookup_by_pdevname("syscon.3");
164 if (IS_ERR(hw->syscon)) {
165 ret = PTR_ERR(hw->syscon);
166 goto err_out;
167 }
168
169 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
170 hw->syncio = devm_ioremap_resource(&pdev->dev, res);
171 if (IS_ERR(hw->syncio)) {
172 ret = PTR_ERR(hw->syncio);
173 goto err_out;
174 }
175
176 /* Disable extended mode due hardware problems */
177 regmap_update_bits(hw->syscon, SYSCON_OFFSET, SYSCON3_ADCCON, 0);
178
179 /* Clear possible pending interrupt */
180 readl(hw->syncio);
181
182 ret = devm_request_irq(&pdev->dev, irq, spi_clps711x_isr, 0,
183 dev_name(&pdev->dev), master);
184 if (ret)
185 goto err_out;
186
187 ret = devm_spi_register_master(&pdev->dev, master);
188 if (!ret) {
189 dev_info(&pdev->dev,
190 "SPI bus driver initialized. Master clock %u Hz\n",
191 master->max_speed_hz);
192 return 0;
193 }
194
195 dev_err(&pdev->dev, "Failed to register master\n");
196
197err_out:
198 spi_master_put(master);
199
200 return ret;
201}
202
203static struct platform_driver clps711x_spi_driver = {
204 .driver = {
205 .name = DRIVER_NAME,
206 },
207 .probe = spi_clps711x_probe,
208};
209module_platform_driver(clps711x_spi_driver);
210
211MODULE_LICENSE("GPL");
212MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
213MODULE_DESCRIPTION("CLPS711X SPI bus driver");
214MODULE_ALIAS("platform:" DRIVER_NAME);