Loading...
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * CLPS711X SPI bus driver
4 *
5 * Copyright (C) 2012-2016 Alexander Shiyan <shc_work@mail.ru>
6 */
7
8#include <linux/io.h>
9#include <linux/clk.h>
10#include <linux/gpio/consumer.h>
11#include <linux/module.h>
12#include <linux/of.h>
13#include <linux/interrupt.h>
14#include <linux/platform_device.h>
15#include <linux/regmap.h>
16#include <linux/mfd/syscon.h>
17#include <linux/mfd/syscon/clps711x.h>
18#include <linux/spi/spi.h>
19
20#define DRIVER_NAME "clps711x-spi"
21
22#define SYNCIO_FRMLEN(x) ((x) << 8)
23#define SYNCIO_TXFRMEN (1 << 14)
24
25struct spi_clps711x_data {
26 void __iomem *syncio;
27 struct regmap *syscon;
28 struct clk *spi_clk;
29
30 u8 *tx_buf;
31 u8 *rx_buf;
32 unsigned int bpw;
33 int len;
34};
35
36static int spi_clps711x_prepare_message(struct spi_controller *host,
37 struct spi_message *msg)
38{
39 struct spi_clps711x_data *hw = spi_controller_get_devdata(host);
40 struct spi_device *spi = msg->spi;
41
42 /* Setup mode for transfer */
43 return regmap_update_bits(hw->syscon, SYSCON_OFFSET, SYSCON3_ADCCKNSEN,
44 (spi->mode & SPI_CPHA) ?
45 SYSCON3_ADCCKNSEN : 0);
46}
47
48static int spi_clps711x_transfer_one(struct spi_controller *host,
49 struct spi_device *spi,
50 struct spi_transfer *xfer)
51{
52 struct spi_clps711x_data *hw = spi_controller_get_devdata(host);
53 u8 data;
54
55 clk_set_rate(hw->spi_clk, xfer->speed_hz ? : spi->max_speed_hz);
56
57 hw->len = xfer->len;
58 hw->bpw = xfer->bits_per_word;
59 hw->tx_buf = (u8 *)xfer->tx_buf;
60 hw->rx_buf = (u8 *)xfer->rx_buf;
61
62 /* Initiate transfer */
63 data = hw->tx_buf ? *hw->tx_buf++ : 0;
64 writel(data | SYNCIO_FRMLEN(hw->bpw) | SYNCIO_TXFRMEN, hw->syncio);
65
66 return 1;
67}
68
69static irqreturn_t spi_clps711x_isr(int irq, void *dev_id)
70{
71 struct spi_controller *host = dev_id;
72 struct spi_clps711x_data *hw = spi_controller_get_devdata(host);
73 u8 data;
74
75 /* Handle RX */
76 data = readb(hw->syncio);
77 if (hw->rx_buf)
78 *hw->rx_buf++ = data;
79
80 /* Handle TX */
81 if (--hw->len > 0) {
82 data = hw->tx_buf ? *hw->tx_buf++ : 0;
83 writel(data | SYNCIO_FRMLEN(hw->bpw) | SYNCIO_TXFRMEN,
84 hw->syncio);
85 } else
86 spi_finalize_current_transfer(host);
87
88 return IRQ_HANDLED;
89}
90
91static int spi_clps711x_probe(struct platform_device *pdev)
92{
93 struct device_node *np = pdev->dev.of_node;
94 struct spi_clps711x_data *hw;
95 struct spi_controller *host;
96 int irq, ret;
97
98 irq = platform_get_irq(pdev, 0);
99 if (irq < 0)
100 return irq;
101
102 host = spi_alloc_host(&pdev->dev, sizeof(*hw));
103 if (!host)
104 return -ENOMEM;
105
106 host->use_gpio_descriptors = true;
107 host->bus_num = -1;
108 host->mode_bits = SPI_CPHA | SPI_CS_HIGH;
109 host->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 8);
110 host->dev.of_node = pdev->dev.of_node;
111 host->prepare_message = spi_clps711x_prepare_message;
112 host->transfer_one = spi_clps711x_transfer_one;
113
114 hw = spi_controller_get_devdata(host);
115
116 hw->spi_clk = devm_clk_get(&pdev->dev, NULL);
117 if (IS_ERR(hw->spi_clk)) {
118 ret = PTR_ERR(hw->spi_clk);
119 goto err_out;
120 }
121
122 hw->syscon = syscon_regmap_lookup_by_phandle(np, "syscon");
123 if (IS_ERR(hw->syscon)) {
124 ret = PTR_ERR(hw->syscon);
125 goto err_out;
126 }
127
128 hw->syncio = devm_platform_ioremap_resource(pdev, 0);
129 if (IS_ERR(hw->syncio)) {
130 ret = PTR_ERR(hw->syncio);
131 goto err_out;
132 }
133
134 /* Disable extended mode due hardware problems */
135 regmap_update_bits(hw->syscon, SYSCON_OFFSET, SYSCON3_ADCCON, 0);
136
137 /* Clear possible pending interrupt */
138 readl(hw->syncio);
139
140 ret = devm_request_irq(&pdev->dev, irq, spi_clps711x_isr, 0,
141 dev_name(&pdev->dev), host);
142 if (ret)
143 goto err_out;
144
145 ret = devm_spi_register_controller(&pdev->dev, host);
146 if (!ret)
147 return 0;
148
149err_out:
150 spi_controller_put(host);
151
152 return ret;
153}
154
155static const struct of_device_id clps711x_spi_dt_ids[] = {
156 { .compatible = "cirrus,ep7209-spi", },
157 { }
158};
159MODULE_DEVICE_TABLE(of, clps711x_spi_dt_ids);
160
161static struct platform_driver clps711x_spi_driver = {
162 .driver = {
163 .name = DRIVER_NAME,
164 .of_match_table = clps711x_spi_dt_ids,
165 },
166 .probe = spi_clps711x_probe,
167};
168module_platform_driver(clps711x_spi_driver);
169
170MODULE_LICENSE("GPL");
171MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
172MODULE_DESCRIPTION("CLPS711X SPI bus driver");
173MODULE_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);