1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2017 Sanechips Technology Co., Ltd.
4 * Copyright 2017 Linaro Ltd.
8 #include <linux/component.h>
9 #include <linux/mfd/syscon.h>
10 #include <linux/module.h>
11 #include <linux/platform_device.h>
12 #include <linux/regmap.h>
14 #include <drm/drm_atomic_helper.h>
15 #include <drm/drm_print.h>
16 #include <drm/drm_probe_helper.h>
18 #include "zx_drm_drv.h"
19 #include "zx_vga_regs.h"
22 struct zx_vga_pwrctrl {
23 struct regmap *regmap;
29 struct i2c_adapter adap;
34 struct drm_connector connector;
35 struct drm_encoder encoder;
36 struct zx_vga_i2c *ddc;
40 struct zx_vga_pwrctrl pwrctrl;
41 struct completion complete;
45 #define to_zx_vga(x) container_of(x, struct zx_vga, x)
47 static void zx_vga_encoder_enable(struct drm_encoder *encoder)
49 struct zx_vga *vga = to_zx_vga(encoder);
50 struct zx_vga_pwrctrl *pwrctrl = &vga->pwrctrl;
52 /* Set bit to power up VGA DACs */
53 regmap_update_bits(pwrctrl->regmap, pwrctrl->reg, pwrctrl->mask,
56 vou_inf_enable(VOU_VGA, encoder->crtc);
59 static void zx_vga_encoder_disable(struct drm_encoder *encoder)
61 struct zx_vga *vga = to_zx_vga(encoder);
62 struct zx_vga_pwrctrl *pwrctrl = &vga->pwrctrl;
64 vou_inf_disable(VOU_VGA, encoder->crtc);
66 /* Clear bit to power down VGA DACs */
67 regmap_update_bits(pwrctrl->regmap, pwrctrl->reg, pwrctrl->mask, 0);
70 static const struct drm_encoder_helper_funcs zx_vga_encoder_helper_funcs = {
71 .enable = zx_vga_encoder_enable,
72 .disable = zx_vga_encoder_disable,
75 static const struct drm_encoder_funcs zx_vga_encoder_funcs = {
76 .destroy = drm_encoder_cleanup,
79 static int zx_vga_connector_get_modes(struct drm_connector *connector)
81 struct zx_vga *vga = to_zx_vga(connector);
86 * Clear both detection bits to switch I2C bus from device
87 * detecting to EDID reading.
89 zx_writel(vga->mmio + VGA_AUTO_DETECT_SEL, 0);
91 edid = drm_get_edid(connector, &vga->ddc->adap);
94 * If EDID reading fails, we set the device state into
95 * disconnected. Locking is not required here, since the
96 * VGA_AUTO_DETECT_SEL register write in irq handler cannot
97 * be triggered when both detection bits are cleared as above.
99 zx_writel(vga->mmio + VGA_AUTO_DETECT_SEL,
100 VGA_DETECT_SEL_NO_DEVICE);
101 vga->connected = false;
106 * As edid reading succeeds, device must be connected, so we set
107 * up detection bit for unplug interrupt here.
109 zx_writel(vga->mmio + VGA_AUTO_DETECT_SEL, VGA_DETECT_SEL_HAS_DEVICE);
111 drm_connector_update_edid_property(connector, edid);
112 ret = drm_add_edid_modes(connector, edid);
118 static enum drm_mode_status
119 zx_vga_connector_mode_valid(struct drm_connector *connector,
120 struct drm_display_mode *mode)
125 static struct drm_connector_helper_funcs zx_vga_connector_helper_funcs = {
126 .get_modes = zx_vga_connector_get_modes,
127 .mode_valid = zx_vga_connector_mode_valid,
130 static enum drm_connector_status
131 zx_vga_connector_detect(struct drm_connector *connector, bool force)
133 struct zx_vga *vga = to_zx_vga(connector);
135 return vga->connected ? connector_status_connected :
136 connector_status_disconnected;
139 static const struct drm_connector_funcs zx_vga_connector_funcs = {
140 .fill_modes = drm_helper_probe_single_connector_modes,
141 .detect = zx_vga_connector_detect,
142 .destroy = drm_connector_cleanup,
143 .reset = drm_atomic_helper_connector_reset,
144 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
145 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
148 static int zx_vga_register(struct drm_device *drm, struct zx_vga *vga)
150 struct drm_encoder *encoder = &vga->encoder;
151 struct drm_connector *connector = &vga->connector;
152 struct device *dev = vga->dev;
155 encoder->possible_crtcs = VOU_CRTC_MASK;
157 ret = drm_encoder_init(drm, encoder, &zx_vga_encoder_funcs,
158 DRM_MODE_ENCODER_DAC, NULL);
160 DRM_DEV_ERROR(dev, "failed to init encoder: %d\n", ret);
164 drm_encoder_helper_add(encoder, &zx_vga_encoder_helper_funcs);
166 vga->connector.polled = DRM_CONNECTOR_POLL_HPD;
168 ret = drm_connector_init(drm, connector, &zx_vga_connector_funcs,
169 DRM_MODE_CONNECTOR_VGA);
171 DRM_DEV_ERROR(dev, "failed to init connector: %d\n", ret);
175 drm_connector_helper_add(connector, &zx_vga_connector_helper_funcs);
177 ret = drm_connector_attach_encoder(connector, encoder);
179 DRM_DEV_ERROR(dev, "failed to attach encoder: %d\n", ret);
180 goto clean_connector;
186 drm_connector_cleanup(connector);
188 drm_encoder_cleanup(encoder);
192 static int zx_vga_pwrctrl_init(struct zx_vga *vga)
194 struct zx_vga_pwrctrl *pwrctrl = &vga->pwrctrl;
195 struct device *dev = vga->dev;
196 struct of_phandle_args out_args;
197 struct regmap *regmap;
200 ret = of_parse_phandle_with_fixed_args(dev->of_node,
201 "zte,vga-power-control", 2, 0, &out_args);
205 regmap = syscon_node_to_regmap(out_args.np);
206 if (IS_ERR(regmap)) {
207 ret = PTR_ERR(regmap);
211 pwrctrl->regmap = regmap;
212 pwrctrl->reg = out_args.args[0];
213 pwrctrl->mask = out_args.args[1];
216 of_node_put(out_args.np);
220 static int zx_vga_i2c_read(struct zx_vga *vga, struct i2c_msg *msg)
227 reinit_completion(&vga->complete);
229 /* Select combo write */
230 zx_writel_mask(vga->mmio + VGA_CMD_CFG, VGA_CMD_COMBO, VGA_CMD_COMBO);
231 zx_writel_mask(vga->mmio + VGA_CMD_CFG, VGA_CMD_RW, 0);
237 zx_writel_mask(vga->mmio + VGA_RXF_CTRL, VGA_RX_FIFO_CLEAR,
240 /* Data offset to read from */
241 zx_writel(vga->mmio + VGA_SUB_ADDR, offset);
243 /* Kick off the transfer */
244 zx_writel_mask(vga->mmio + VGA_CMD_CFG, VGA_CMD_TRANS,
247 if (!wait_for_completion_timeout(&vga->complete,
248 msecs_to_jiffies(1000))) {
249 DRM_DEV_ERROR(vga->dev, "transfer timeout\n");
253 cnt = zx_readl(vga->mmio + VGA_RXF_STATUS);
254 cnt = (cnt & VGA_RXF_COUNT_MASK) >> VGA_RXF_COUNT_SHIFT;
255 /* FIFO status may report more data than we need to read */
256 cnt = min_t(u32, len, cnt);
258 for (i = 0; i < cnt; i++)
259 *buf++ = zx_readl(vga->mmio + VGA_DATA);
268 static int zx_vga_i2c_write(struct zx_vga *vga, struct i2c_msg *msg)
271 * The DDC I2C adapter is only for reading EDID data, so we assume
272 * that the write to this adapter must be the EDID data offset.
274 if ((msg->len != 1) || ((msg->addr != DDC_ADDR)))
277 /* Hardware will take care of the slave address shifting */
278 zx_writel(vga->mmio + VGA_DEVICE_ADDR, msg->addr);
283 static int zx_vga_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
286 struct zx_vga *vga = i2c_get_adapdata(adap);
287 struct zx_vga_i2c *ddc = vga->ddc;
291 mutex_lock(&ddc->lock);
293 for (i = 0; i < num; i++) {
294 if (msgs[i].flags & I2C_M_RD)
295 ret = zx_vga_i2c_read(vga, &msgs[i]);
297 ret = zx_vga_i2c_write(vga, &msgs[i]);
306 mutex_unlock(&ddc->lock);
311 static u32 zx_vga_i2c_func(struct i2c_adapter *adapter)
313 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
316 static const struct i2c_algorithm zx_vga_algorithm = {
317 .master_xfer = zx_vga_i2c_xfer,
318 .functionality = zx_vga_i2c_func,
321 static int zx_vga_ddc_register(struct zx_vga *vga)
323 struct device *dev = vga->dev;
324 struct i2c_adapter *adap;
325 struct zx_vga_i2c *ddc;
328 ddc = devm_kzalloc(dev, sizeof(*ddc), GFP_KERNEL);
333 mutex_init(&ddc->lock);
336 adap->owner = THIS_MODULE;
337 adap->class = I2C_CLASS_DDC;
338 adap->dev.parent = dev;
339 adap->algo = &zx_vga_algorithm;
340 snprintf(adap->name, sizeof(adap->name), "zx vga i2c");
342 ret = i2c_add_adapter(adap);
344 DRM_DEV_ERROR(dev, "failed to add I2C adapter: %d\n", ret);
348 i2c_set_adapdata(adap, vga);
353 static irqreturn_t zx_vga_irq_thread(int irq, void *dev_id)
355 struct zx_vga *vga = dev_id;
357 drm_helper_hpd_irq_event(vga->connector.dev);
362 static irqreturn_t zx_vga_irq_handler(int irq, void *dev_id)
364 struct zx_vga *vga = dev_id;
367 status = zx_readl(vga->mmio + VGA_I2C_STATUS);
369 /* Clear interrupt status */
370 zx_writel_mask(vga->mmio + VGA_I2C_STATUS, VGA_CLEAR_IRQ,
373 if (status & VGA_DEVICE_CONNECTED) {
375 * Since VGA_DETECT_SEL bits need to be reset for switching DDC
376 * bus from device detection to EDID read, rather than setting
377 * up HAS_DEVICE bit here, we need to do that in .get_modes
378 * hook for unplug detecting after EDID read succeeds.
380 vga->connected = true;
381 return IRQ_WAKE_THREAD;
384 if (status & VGA_DEVICE_DISCONNECTED) {
385 zx_writel(vga->mmio + VGA_AUTO_DETECT_SEL,
386 VGA_DETECT_SEL_NO_DEVICE);
387 vga->connected = false;
388 return IRQ_WAKE_THREAD;
391 if (status & VGA_TRANS_DONE) {
392 complete(&vga->complete);
399 static void zx_vga_hw_init(struct zx_vga *vga)
401 unsigned long ref = clk_get_rate(vga->i2c_wclk);
405 * Set up I2C fast speed divider per formula below to get 400kHz.
406 * scl = ref / ((div + 1) * 4)
408 div = DIV_ROUND_UP(ref / 1000, 400 * 4) - 1;
409 zx_writel(vga->mmio + VGA_CLK_DIV_FS, div);
411 /* Set up device detection */
412 zx_writel(vga->mmio + VGA_AUTO_DETECT_PARA, 0x80);
413 zx_writel(vga->mmio + VGA_AUTO_DETECT_SEL, VGA_DETECT_SEL_NO_DEVICE);
416 * We need to poke monitor via DDC bus to get connection irq
419 zx_writel(vga->mmio + VGA_DEVICE_ADDR, DDC_ADDR);
420 zx_writel_mask(vga->mmio + VGA_CMD_CFG, VGA_CMD_TRANS, VGA_CMD_TRANS);
423 static int zx_vga_bind(struct device *dev, struct device *master, void *data)
425 struct platform_device *pdev = to_platform_device(dev);
426 struct drm_device *drm = data;
427 struct resource *res;
432 vga = devm_kzalloc(dev, sizeof(*vga), GFP_KERNEL);
437 dev_set_drvdata(dev, vga);
439 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
440 vga->mmio = devm_ioremap_resource(dev, res);
441 if (IS_ERR(vga->mmio))
442 return PTR_ERR(vga->mmio);
444 irq = platform_get_irq(pdev, 0);
448 vga->i2c_wclk = devm_clk_get(dev, "i2c_wclk");
449 if (IS_ERR(vga->i2c_wclk)) {
450 ret = PTR_ERR(vga->i2c_wclk);
451 DRM_DEV_ERROR(dev, "failed to get i2c_wclk: %d\n", ret);
455 ret = zx_vga_pwrctrl_init(vga);
457 DRM_DEV_ERROR(dev, "failed to init power control: %d\n", ret);
461 ret = zx_vga_ddc_register(vga);
463 DRM_DEV_ERROR(dev, "failed to register ddc: %d\n", ret);
467 ret = zx_vga_register(drm, vga);
469 DRM_DEV_ERROR(dev, "failed to register vga: %d\n", ret);
473 init_completion(&vga->complete);
475 ret = devm_request_threaded_irq(dev, irq, zx_vga_irq_handler,
476 zx_vga_irq_thread, IRQF_SHARED,
479 DRM_DEV_ERROR(dev, "failed to request threaded irq: %d\n", ret);
483 ret = clk_prepare_enable(vga->i2c_wclk);
492 static void zx_vga_unbind(struct device *dev, struct device *master,
495 struct zx_vga *vga = dev_get_drvdata(dev);
497 clk_disable_unprepare(vga->i2c_wclk);
500 static const struct component_ops zx_vga_component_ops = {
502 .unbind = zx_vga_unbind,
505 static int zx_vga_probe(struct platform_device *pdev)
507 return component_add(&pdev->dev, &zx_vga_component_ops);
510 static int zx_vga_remove(struct platform_device *pdev)
512 component_del(&pdev->dev, &zx_vga_component_ops);
516 static const struct of_device_id zx_vga_of_match[] = {
517 { .compatible = "zte,zx296718-vga", },
520 MODULE_DEVICE_TABLE(of, zx_vga_of_match);
522 struct platform_driver zx_vga_driver = {
523 .probe = zx_vga_probe,
524 .remove = zx_vga_remove,
527 .of_match_table = zx_vga_of_match,