Re: [RFC v2 2/2] drm/bridge: Add I2C based driver for ps8640 bridge

[Philipp Zabel]

Hi Jitao,

some things I missed before.

Am Montag, den 02.11.2015, 10:09 +0800 schrieb Jitao Shi:
[...]
> +static int ps8640_regr(struct i2c_client *client, u16 i2c_addr,
> +u8 reg, u8 *value)
> +{
> + int ret;
> +
> + client->addr = i2c_addr;

I think i2c_new_dummy should be used to create additional clients for
the secondary addresses, instead of changing the address of the client
with every transfer.

> + ret = i2c_master_send(client, , 1);
> + if (ret <= 0) {
> + DRM_ERROR("Failed to send i2c command, ret=%d\n", ret);
> + return ret;
> + }
> +
> + ret = i2c_master_recv(client, value, 1);
> + if (ret <= 0) {
> + DRM_ERROR("Failed to recv i2c data, ret=%d\n", ret);
> + return ret;
> + }
> +
> + return 0;
> +}
[...]
> +static int ps8640_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct device *dev = >dev;
> + struct ps8640 *ps_bridge;
> + struct device_node *np = dev->of_node;
> + struct device_node *in_ep, *out_ep;
> + struct device_node *panel_node = NULL;
> + int ret;
> + u32 temp_reg;
> +
> + ps_bridge = devm_kzalloc(dev, sizeof(*ps_bridge), GFP_KERNEL);
> + if (!ps_bridge)
> + return -ENOMEM;
> +
> + in_ep = of_graph_get_next_endpoint(np, NULL);
> + if (in_ep) {
> + out_ep = of_graph_get_next_endpoint(np, in_ep);
> + of_node_put(in_ep);
> + if (out_ep) {
> + panel_node = of_graph_get_remote_port_parent(out_ep);
> + of_node_put(out_ep);
> + }
> + }
> + if (panel_node) {
> + ps_bridge->panel = of_drm_find_panel(panel_node);
> + of_node_put(panel_node);
> + if (!ps_bridge->panel)
> + return -EPROBE_DEFER;
> + }
> +
> + ps_bridge->client = client;
> +
> + ps_bridge->pwr_3v3_supply = devm_regulator_get(dev, "vdd33-supply");

Should be "vdd3", regulator_get will add the "-supply" suffix.

> + if (IS_ERR(ps_bridge->pwr_3v3_supply)) {
> + dev_err(dev, "cannot get ps_bridge->pwr_3v3_supply\n");
> + return PTR_ERR(ps_bridge->pwr_3v3_supply);
> + }
> +
> + ps_bridge->pwr_1v2_supply = devm_regulator_get(dev, "vdd12-supply");

Same here, "vdd12".

> + if (IS_ERR(ps_bridge->pwr_1v2_supply)) {
> + dev_err(dev, "cannot get ps_bridge->pwr_1v2_supply\n");
> + return PTR_ERR(ps_bridge->pwr_1v2_supply);
> + }
> +
> + ps_bridge->gpio_mode_sel_n = devm_gpiod_get(>dev, "mode-sel",
> + GPIOD_OUT_HIGH);
> + if (IS_ERR(ps_bridge->gpio_mode_sel_n)) {
> + ret = PTR_ERR(ps_bridge->gpio_mode_sel_n);
> + DRM_ERROR("cannot get gpio_mode_sel_n %d\n", ret);
> + return ret;
> + }
> +
> + ret = gpiod_direction_output(ps_bridge->gpio_mode_sel_n, 1);
> + if (ret) {
> + DRM_ERROR("cannot configure gpio_mode_sel_n\n");
> + return ret;
> + }
> +
> + ps_bridge->gpio_slp_n = devm_gpiod_get(>dev, "sleep-gpios",
> +GPIOD_OUT_HIGH);

Should be "sleep", gpiod_get will add the "-gpios" suffix.

> + if (IS_ERR(ps_bridge->gpio_slp_n)) {
> + ret = PTR_ERR(ps_bridge->gpio_slp_n);
> + DRM_ERROR("cannot get gpio_slp_n %d\n", ret);
> + return ret;
> + }
> +
> + ret = gpiod_direction_output(ps_bridge->gpio_slp_n, 1);
> + if (ret) {
> + DRM_ERROR("cannot configure gpio_slp_n\n");
> + return ret;
> + }

This can be removed, the "devm_gpiod_get(..., GPIOD_OUT_HIGH);" already
does the same.

> +
> + ps_bridge->gpio_rst_n = devm_gpiod_get(>dev, "reset",
> +GPIOD_OUT_HIGH);
> + if (IS_ERR(ps_bridge->gpio_rst_n)) {
> + ret = PTR_ERR(ps_bridge->gpio_rst_n);
> + DRM_ERROR("cannot get gpio_rst_n %d\n", ret);
> + return ret;
> + }
> +
> + ret = gpiod_direction_output(ps_bridge->gpio_rst_n, 1);
> + if (ret) {
> + DRM_ERROR("cannot configure gpio_rst_n\n");
> + return ret;
> + }

Same here, the gpiod_direction_output can be removed.

best regards
Philipp

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Re: [RFC v2 2/2] drm/bridge: Add I2C based driver for ps8640 bridge

[Philipp Zabel]

Hi Jitao,

some things I missed before.

Am Montag, den 02.11.2015, 10:09 +0800 schrieb Jitao Shi:
[...]
> +static int ps8640_regr(struct i2c_client *client, u16 i2c_addr,
> +u8 reg, u8 *value)
> +{
> + int ret;
> +
> + client->addr = i2c_addr;

I think i2c_new_dummy should be used to create additional clients for
the secondary addresses, instead of changing the address of the client
with every transfer.

> + ret = i2c_master_send(client, , 1);
> + if (ret <= 0) {
> + DRM_ERROR("Failed to send i2c command, ret=%d\n", ret);
> + return ret;
> + }
> +
> + ret = i2c_master_recv(client, value, 1);
> + if (ret <= 0) {
> + DRM_ERROR("Failed to recv i2c data, ret=%d\n", ret);
> + return ret;
> + }
> +
> + return 0;
> +}
[...]
> +static int ps8640_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct device *dev = >dev;
> + struct ps8640 *ps_bridge;
> + struct device_node *np = dev->of_node;
> + struct device_node *in_ep, *out_ep;
> + struct device_node *panel_node = NULL;
> + int ret;
> + u32 temp_reg;
> +
> + ps_bridge = devm_kzalloc(dev, sizeof(*ps_bridge), GFP_KERNEL);
> + if (!ps_bridge)
> + return -ENOMEM;
> +
> + in_ep = of_graph_get_next_endpoint(np, NULL);
> + if (in_ep) {
> + out_ep = of_graph_get_next_endpoint(np, in_ep);
> + of_node_put(in_ep);
> + if (out_ep) {
> + panel_node = of_graph_get_remote_port_parent(out_ep);
> + of_node_put(out_ep);
> + }
> + }
> + if (panel_node) {
> + ps_bridge->panel = of_drm_find_panel(panel_node);
> + of_node_put(panel_node);
> + if (!ps_bridge->panel)
> + return -EPROBE_DEFER;
> + }
> +
> + ps_bridge->client = client;
> +
> + ps_bridge->pwr_3v3_supply = devm_regulator_get(dev, "vdd33-supply");

Should be "vdd3", regulator_get will add the "-supply" suffix.

> + if (IS_ERR(ps_bridge->pwr_3v3_supply)) {
> + dev_err(dev, "cannot get ps_bridge->pwr_3v3_supply\n");
> + return PTR_ERR(ps_bridge->pwr_3v3_supply);
> + }
> +
> + ps_bridge->pwr_1v2_supply = devm_regulator_get(dev, "vdd12-supply");

Same here, "vdd12".

> + if (IS_ERR(ps_bridge->pwr_1v2_supply)) {
> + dev_err(dev, "cannot get ps_bridge->pwr_1v2_supply\n");
> + return PTR_ERR(ps_bridge->pwr_1v2_supply);
> + }
> +
> + ps_bridge->gpio_mode_sel_n = devm_gpiod_get(>dev, "mode-sel",
> + GPIOD_OUT_HIGH);
> + if (IS_ERR(ps_bridge->gpio_mode_sel_n)) {
> + ret = PTR_ERR(ps_bridge->gpio_mode_sel_n);
> + DRM_ERROR("cannot get gpio_mode_sel_n %d\n", ret);
> + return ret;
> + }
> +
> + ret = gpiod_direction_output(ps_bridge->gpio_mode_sel_n, 1);
> + if (ret) {
> + DRM_ERROR("cannot configure gpio_mode_sel_n\n");
> + return ret;
> + }
> +
> + ps_bridge->gpio_slp_n = devm_gpiod_get(>dev, "sleep-gpios",
> +GPIOD_OUT_HIGH);

Should be "sleep", gpiod_get will add the "-gpios" suffix.

> + if (IS_ERR(ps_bridge->gpio_slp_n)) {
> + ret = PTR_ERR(ps_bridge->gpio_slp_n);
> + DRM_ERROR("cannot get gpio_slp_n %d\n", ret);
> + return ret;
> + }
> +
> + ret = gpiod_direction_output(ps_bridge->gpio_slp_n, 1);
> + if (ret) {
> + DRM_ERROR("cannot configure gpio_slp_n\n");
> + return ret;
> + }

This can be removed, the "devm_gpiod_get(..., GPIOD_OUT_HIGH);" already
does the same.

> +
> + ps_bridge->gpio_rst_n = devm_gpiod_get(>dev, "reset",
> +GPIOD_OUT_HIGH);
> + if (IS_ERR(ps_bridge->gpio_rst_n)) {
> + ret = PTR_ERR(ps_bridge->gpio_rst_n);
> + DRM_ERROR("cannot get gpio_rst_n %d\n", ret);
> + return ret;
> + }
> +
> + ret = gpiod_direction_output(ps_bridge->gpio_rst_n, 1);
> + if (ret) {
> + DRM_ERROR("cannot configure gpio_rst_n\n");
> + return ret;
> + }

Same here, the gpiod_direction_output can be removed.

best regards
Philipp

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Re: [RFC v2 2/2] drm/bridge: Add I2C based driver for ps8640 bridge

[jitao shi]

Hi Philipp

I'll fixed those comments on V3.

Thank you very much.

Best Regards.

On Mon, 2015-11-02 at 12:34 +0100, Philipp Zabel wrote:
> Hi Jitao,
> 
> a few comments below.
> 
> Am Montag, den 02.11.2015, 11:54 +0800 schrieb jitao shi:
> [...]
> > > +static int ps8640_check_valid_id(struct ps8640 *ps_bridge)
> 
> This could be bool and return true/false.
> 
> > > +{
> > > + struct i2c_client *client = ps_bridge->client;
> > > + u8 rev_id_low, rev_id_high, chip_id_low, chip_id_high;
> > > + int retry_cnt = 0;
> > > +
> > > + do {
> > > + ps8640_regr(client, ps_bridge->base_reg + 4, PAGE4_CHIP_H,
> > > + _id_high);
> > > + if (chip_id_high != 0x30)
> > > + DRM_INFO("chip_id_high = 0x%x\n", chip_id_high);
> > > + } while ((retry_cnt++ < 2) && (chip_id_high != 0x30));
> > > +
> > > + ps8640_regr(client, ps_bridge->base_reg + 4, PAGE4_REV_L, _id_low);
> > > + ps8640_regr(client, ps_bridge->base_reg + 4, PAGE4_REV_H, _id_high);
> > > + ps8640_regr(client, ps_bridge->base_reg + 4, PAGE4_CHIP_L,
> > > + _id_low);
> > > +
> > > + if ((rev_id_low == 0x00) && (rev_id_high == 0x0a) &&
> > > + (chip_id_low == 0x00) && (chip_id_high == 0x30))
> > > + return 1;
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static void ps8640_show_mcu_fw_version(struct ps8640 *ps_bridge)
> > > +{
> > > + struct i2c_client *client = ps_bridge->client;
> > > + u8 major_ver, minor_ver;
> > > +
> > > + ps8640_regr(client, ps_bridge->base_reg + 5, 0x4, _ver);
> > > + ps8640_regr(client, ps_bridge->base_reg + 5, 0x5, _ver);
> > > +
> > > + DRM_INFO_ONCE("ps8640 rom fw version %d.%d\n", major_ver, minor_ver);
> > > +}
> > > +
> > > +static int ps8640_bdg_enable(struct ps8640 *ps_bridge)
> > > +{
> > > + struct i2c_client *client = ps_bridge->client;
> > > +
> > > + if (ps8640_check_valid_id(ps_bridge)) {
> > > + ps8640_regw(client, ps_bridge->base_reg + 3, 0xfe, 0x13);
> > > + ps8640_regw(client, ps_bridge->base_reg + 3, 0xff, 0x18);
> > > + ps8640_regw(client, ps_bridge->base_reg + 3, 0xfe, 0x13);
> > > + ps8640_regw(client, ps_bridge->base_reg + 3, 0xff, 0x1c);
> 
> Can you introduce #defines with descriptive names for those magic
> constants and register offsets, and maybe also i2c address offsets?
> 
> > > +
> > > + return 0;
> > > + }
> > > +
> > > + return -1;
> 
> Never return -1 to signal a problem.
> If there was an error, use a proper error code.
> 
> > > +}
> > > +
> > > +static void ps8640_prepare(struct ps8640 *ps_bridge)
> > > +{
> > > + struct i2c_client *client = ps_bridge->client;
> > > + int err, retry_cnt = 0;
> > > + u8 set_vdo_done;
> > > +
> > > + if (ps_bridge->enabled)
> > > + return;
> > > +
> > > + if (drm_panel_prepare(ps_bridge->panel)) {
> > > + DRM_ERROR("failed to prepare panel\n");
> > > + return;
> > > + }
> > > +
> > > + err = regulator_enable(ps_bridge->pwr_1v2_supply);
> > > + if (err < 0) {
> > > + DRM_ERROR("failed to enable pwr_1v2_supply: %d\n", err);
> 
> Missing panel unprepare.
> 
> > > + return;
> > > + }
> > > +
> > > + err = regulator_enable(ps_bridge->pwr_3v3_supply);
> > > + if (err < 0) {
> > > + DRM_ERROR("failed to enable pwr_3v3_supply: %d\n", err);
> 
> Missing panel unprepare and vdd12 regulator disable.
> 
> > > + return;
> > > + }
> > > +
> > > + gpiod_set_value(ps_bridge->gpio_slp_n, 1);
> > > + gpiod_set_value(ps_bridge->gpio_rst_n, 0);
> > > + usleep_range(500, 700);
> > > + gpiod_set_value(ps_bridge->gpio_rst_n, 1);
> > > +
> > > + do {
> > > + msleep(50);
> > > + ps8640_regr(client, ps_bridge->base_reg + 2, PAGE2_GPIO_H,
> > > + _vdo_done);
> > > + } while ((retry_cnt++ < 70) && ((set_vdo_done & PS_GPIO9) != PS_GPIO9));
> > > +
> > > + ps8640_show_mcu_fw_version(ps_bridge);
> > > + ps_bridge->enabled = true;
> > > +}
> > > +
> > > +static void ps8640_pre_enable(struct drm_bridge *bridge)
> > > +{
> > > + struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
> > > +
> > > + ps8640_prepare(ps_bridge);
> > > +}
> > > +
> > > +static void ps8640_enable(struct drm_bridge *bridge)
> > > +{
> > > + struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
> > > +
> > > + ps8640_bdg_enable(ps_bridge);
> > > +
> > > + if (drm_panel_enable(ps_bridge->panel)) {
> > > + DRM_ERROR("failed to enable panel\n");
> > > + return;
> 
> The return is superfluous.
> 
> > > + }
> > > +}
> > > +
> > > +static void ps8640_disable(struct drm_bridge *bridge)
> > > +{
> > > + struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
> > > +
> > > + if (!ps_bridge->enabled)
> > > + return;
> > > +
> > > + ps_bridge->enabled = false;
> > > +
> > > + if (drm_panel_disable(ps_bridge->panel)) {
> > > + DRM_ERROR("failed to disable panel\n");
> > > + return;
> 
> Shouldn't we still disable the bridge, even if panel disable fails?
> 
> > > + }
> > > +
> > > + 

Re: [RFC v2 2/2] drm/bridge: Add I2C based driver for ps8640 bridge

[jitao shi]

Hi Philipp

I'll fixed those comments on V3.

Thank you very much.

Best Regards.

On Mon, 2015-11-02 at 12:34 +0100, Philipp Zabel wrote:
> Hi Jitao,
> 
> a few comments below.
> 
> Am Montag, den 02.11.2015, 11:54 +0800 schrieb jitao shi:
> [...]
> > > +static int ps8640_check_valid_id(struct ps8640 *ps_bridge)
> 
> This could be bool and return true/false.
> 
> > > +{
> > > + struct i2c_client *client = ps_bridge->client;
> > > + u8 rev_id_low, rev_id_high, chip_id_low, chip_id_high;
> > > + int retry_cnt = 0;
> > > +
> > > + do {
> > > + ps8640_regr(client, ps_bridge->base_reg + 4, PAGE4_CHIP_H,
> > > + _id_high);
> > > + if (chip_id_high != 0x30)
> > > + DRM_INFO("chip_id_high = 0x%x\n", chip_id_high);
> > > + } while ((retry_cnt++ < 2) && (chip_id_high != 0x30));
> > > +
> > > + ps8640_regr(client, ps_bridge->base_reg + 4, PAGE4_REV_L, _id_low);
> > > + ps8640_regr(client, ps_bridge->base_reg + 4, PAGE4_REV_H, _id_high);
> > > + ps8640_regr(client, ps_bridge->base_reg + 4, PAGE4_CHIP_L,
> > > + _id_low);
> > > +
> > > + if ((rev_id_low == 0x00) && (rev_id_high == 0x0a) &&
> > > + (chip_id_low == 0x00) && (chip_id_high == 0x30))
> > > + return 1;
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static void ps8640_show_mcu_fw_version(struct ps8640 *ps_bridge)
> > > +{
> > > + struct i2c_client *client = ps_bridge->client;
> > > + u8 major_ver, minor_ver;
> > > +
> > > + ps8640_regr(client, ps_bridge->base_reg + 5, 0x4, _ver);
> > > + ps8640_regr(client, ps_bridge->base_reg + 5, 0x5, _ver);
> > > +
> > > + DRM_INFO_ONCE("ps8640 rom fw version %d.%d\n", major_ver, minor_ver);
> > > +}
> > > +
> > > +static int ps8640_bdg_enable(struct ps8640 *ps_bridge)
> > > +{
> > > + struct i2c_client *client = ps_bridge->client;
> > > +
> > > + if (ps8640_check_valid_id(ps_bridge)) {
> > > + ps8640_regw(client, ps_bridge->base_reg + 3, 0xfe, 0x13);
> > > + ps8640_regw(client, ps_bridge->base_reg + 3, 0xff, 0x18);
> > > + ps8640_regw(client, ps_bridge->base_reg + 3, 0xfe, 0x13);
> > > + ps8640_regw(client, ps_bridge->base_reg + 3, 0xff, 0x1c);
> 
> Can you introduce #defines with descriptive names for those magic
> constants and register offsets, and maybe also i2c address offsets?
> 
> > > +
> > > + return 0;
> > > + }
> > > +
> > > + return -1;
> 
> Never return -1 to signal a problem.
> If there was an error, use a proper error code.
> 
> > > +}
> > > +
> > > +static void ps8640_prepare(struct ps8640 *ps_bridge)
> > > +{
> > > + struct i2c_client *client = ps_bridge->client;
> > > + int err, retry_cnt = 0;
> > > + u8 set_vdo_done;
> > > +
> > > + if (ps_bridge->enabled)
> > > + return;
> > > +
> > > + if (drm_panel_prepare(ps_bridge->panel)) {
> > > + DRM_ERROR("failed to prepare panel\n");
> > > + return;
> > > + }
> > > +
> > > + err = regulator_enable(ps_bridge->pwr_1v2_supply);
> > > + if (err < 0) {
> > > + DRM_ERROR("failed to enable pwr_1v2_supply: %d\n", err);
> 
> Missing panel unprepare.
> 
> > > + return;
> > > + }
> > > +
> > > + err = regulator_enable(ps_bridge->pwr_3v3_supply);
> > > + if (err < 0) {
> > > + DRM_ERROR("failed to enable pwr_3v3_supply: %d\n", err);
> 
> Missing panel unprepare and vdd12 regulator disable.
> 
> > > + return;
> > > + }
> > > +
> > > + gpiod_set_value(ps_bridge->gpio_slp_n, 1);
> > > + gpiod_set_value(ps_bridge->gpio_rst_n, 0);
> > > + usleep_range(500, 700);
> > > + gpiod_set_value(ps_bridge->gpio_rst_n, 1);
> > > +
> > > + do {
> > > + msleep(50);
> > > + ps8640_regr(client, ps_bridge->base_reg + 2, PAGE2_GPIO_H,
> > > + _vdo_done);
> > > + } while ((retry_cnt++ < 70) && ((set_vdo_done & PS_GPIO9) != PS_GPIO9));
> > > +
> > > + ps8640_show_mcu_fw_version(ps_bridge);
> > > + ps_bridge->enabled = true;
> > > +}
> > > +
> > > +static void ps8640_pre_enable(struct drm_bridge *bridge)
> > > +{
> > > + struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
> > > +
> > > + ps8640_prepare(ps_bridge);
> > > +}
> > > +
> > > +static void ps8640_enable(struct drm_bridge *bridge)
> > > +{
> > > + struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
> > > +
> > > + ps8640_bdg_enable(ps_bridge);
> > > +
> > > + if (drm_panel_enable(ps_bridge->panel)) {
> > > + DRM_ERROR("failed to enable panel\n");
> > > + return;
> 
> The return is superfluous.
> 
> > > + }
> > > +}
> > > +
> > > +static void ps8640_disable(struct drm_bridge *bridge)
> > > +{
> > > + struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
> > > +
> > > + if (!ps_bridge->enabled)
> > > + return;
> > > +
> > > + ps_bridge->enabled = false;
> > > +
> > > + if (drm_panel_disable(ps_bridge->panel)) {
> > > + DRM_ERROR("failed to disable panel\n");
> > > + return;
> 
> Shouldn't we still disable the bridge, even if panel disable fails?
> 
> > > + }
> > > +
> > > + 

Re: [RFC v2 2/2] drm/bridge: Add I2C based driver for ps8640 bridge

[Philipp Zabel]

Hi Jitao,

a few comments below.

Am Montag, den 02.11.2015, 11:54 +0800 schrieb jitao shi:
[...]
> > +static int ps8640_check_valid_id(struct ps8640 *ps_bridge)

This could be bool and return true/false.

> > +{
> > +   struct i2c_client *client = ps_bridge->client;
> > +   u8 rev_id_low, rev_id_high, chip_id_low, chip_id_high;
> > +   int retry_cnt = 0;
> > +
> > +   do {
> > +   ps8640_regr(client, ps_bridge->base_reg + 4, PAGE4_CHIP_H,
> > +   _id_high);
> > +   if (chip_id_high != 0x30)
> > +   DRM_INFO("chip_id_high = 0x%x\n", chip_id_high);
> > +   } while ((retry_cnt++ < 2) && (chip_id_high != 0x30));
> > +
> > +   ps8640_regr(client, ps_bridge->base_reg + 4, PAGE4_REV_L, _id_low);
> > +   ps8640_regr(client, ps_bridge->base_reg + 4, PAGE4_REV_H, _id_high);
> > +   ps8640_regr(client, ps_bridge->base_reg + 4, PAGE4_CHIP_L,
> > +   _id_low);
> > +
> > +   if ((rev_id_low == 0x00) && (rev_id_high == 0x0a) &&
> > +   (chip_id_low == 0x00) && (chip_id_high == 0x30))
> > +   return 1;
> > +
> > +   return 0;
> > +}
> > +
> > +static void ps8640_show_mcu_fw_version(struct ps8640 *ps_bridge)
> > +{
> > +   struct i2c_client *client = ps_bridge->client;
> > +   u8 major_ver, minor_ver;
> > +
> > +   ps8640_regr(client, ps_bridge->base_reg + 5, 0x4, _ver);
> > +   ps8640_regr(client, ps_bridge->base_reg + 5, 0x5, _ver);
> > +
> > +   DRM_INFO_ONCE("ps8640 rom fw version %d.%d\n", major_ver, minor_ver);
> > +}
> > +
> > +static int ps8640_bdg_enable(struct ps8640 *ps_bridge)
> > +{
> > +   struct i2c_client *client = ps_bridge->client;
> > +
> > +   if (ps8640_check_valid_id(ps_bridge)) {
> > +   ps8640_regw(client, ps_bridge->base_reg + 3, 0xfe, 0x13);
> > +   ps8640_regw(client, ps_bridge->base_reg + 3, 0xff, 0x18);
> > +   ps8640_regw(client, ps_bridge->base_reg + 3, 0xfe, 0x13);
> > +   ps8640_regw(client, ps_bridge->base_reg + 3, 0xff, 0x1c);

Can you introduce #defines with descriptive names for those magic
constants and register offsets, and maybe also i2c address offsets?

> > +
> > +   return 0;
> > +   }
> > +
> > +   return -1;

Never return -1 to signal a problem.
If there was an error, use a proper error code.

> > +}
> > +
> > +static void ps8640_prepare(struct ps8640 *ps_bridge)
> > +{
> > +   struct i2c_client *client = ps_bridge->client;
> > +   int err, retry_cnt = 0;
> > +   u8 set_vdo_done;
> > +
> > +   if (ps_bridge->enabled)
> > +   return;
> > +
> > +   if (drm_panel_prepare(ps_bridge->panel)) {
> > +   DRM_ERROR("failed to prepare panel\n");
> > +   return;
> > +   }
> > +
> > +   err = regulator_enable(ps_bridge->pwr_1v2_supply);
> > +   if (err < 0) {
> > +   DRM_ERROR("failed to enable pwr_1v2_supply: %d\n", err);

Missing panel unprepare.

> > +   return;
> > +   }
> > +
> > +   err = regulator_enable(ps_bridge->pwr_3v3_supply);
> > +   if (err < 0) {
> > +   DRM_ERROR("failed to enable pwr_3v3_supply: %d\n", err);

Missing panel unprepare and vdd12 regulator disable.

> > +   return;
> > +   }
> > +
> > +   gpiod_set_value(ps_bridge->gpio_slp_n, 1);
> > +   gpiod_set_value(ps_bridge->gpio_rst_n, 0);
> > +   usleep_range(500, 700);
> > +   gpiod_set_value(ps_bridge->gpio_rst_n, 1);
> > +
> > +   do {
> > +   msleep(50);
> > +   ps8640_regr(client, ps_bridge->base_reg + 2, PAGE2_GPIO_H,
> > +   _vdo_done);
> > +   } while ((retry_cnt++ < 70) && ((set_vdo_done & PS_GPIO9) != PS_GPIO9));
> > +
> > +   ps8640_show_mcu_fw_version(ps_bridge);
> > +   ps_bridge->enabled = true;
> > +}
> > +
> > +static void ps8640_pre_enable(struct drm_bridge *bridge)
> > +{
> > +   struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
> > +
> > +   ps8640_prepare(ps_bridge);
> > +}
> > +
> > +static void ps8640_enable(struct drm_bridge *bridge)
> > +{
> > +   struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
> > +
> > +   ps8640_bdg_enable(ps_bridge);
> > +
> > +   if (drm_panel_enable(ps_bridge->panel)) {
> > +   DRM_ERROR("failed to enable panel\n");
> > +   return;

The return is superfluous.

> > +   }
> > +}
> > +
> > +static void ps8640_disable(struct drm_bridge *bridge)
> > +{
> > +   struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
> > +
> > +   if (!ps_bridge->enabled)
> > +   return;
> > +
> > +   ps_bridge->enabled = false;
> > +
> > +   if (drm_panel_disable(ps_bridge->panel)) {
> > +   DRM_ERROR("failed to disable panel\n");
> > +   return;

Shouldn't we still disable the bridge, even if panel disable fails?

> > +   }
> > +
> > +   regulator_disable(ps_bridge->pwr_1v2_supply);
> > +   regulator_disable(ps_bridge->pwr_3v3_supply);
> > +   gpiod_set_value(ps_bridge->gpio_rst_n, 0);
> > +   gpiod_set_value(ps_bridge->gpio_slp_n, 0);
> > +}
> > +
> > +static void ps8640_post_disable(struct drm_bridge *bridge)
> > +{
> > +   struct ps8640 

Re: [RFC v2 2/2] drm/bridge: Add I2C based driver for ps8640 bridge

[Philipp Zabel]

Hi Jitao,

a few comments below.

Am Montag, den 02.11.2015, 11:54 +0800 schrieb jitao shi:
[...]
> > +static int ps8640_check_valid_id(struct ps8640 *ps_bridge)

This could be bool and return true/false.

> > +{
> > +   struct i2c_client *client = ps_bridge->client;
> > +   u8 rev_id_low, rev_id_high, chip_id_low, chip_id_high;
> > +   int retry_cnt = 0;
> > +
> > +   do {
> > +   ps8640_regr(client, ps_bridge->base_reg + 4, PAGE4_CHIP_H,
> > +   _id_high);
> > +   if (chip_id_high != 0x30)
> > +   DRM_INFO("chip_id_high = 0x%x\n", chip_id_high);
> > +   } while ((retry_cnt++ < 2) && (chip_id_high != 0x30));
> > +
> > +   ps8640_regr(client, ps_bridge->base_reg + 4, PAGE4_REV_L, _id_low);
> > +   ps8640_regr(client, ps_bridge->base_reg + 4, PAGE4_REV_H, _id_high);
> > +   ps8640_regr(client, ps_bridge->base_reg + 4, PAGE4_CHIP_L,
> > +   _id_low);
> > +
> > +   if ((rev_id_low == 0x00) && (rev_id_high == 0x0a) &&
> > +   (chip_id_low == 0x00) && (chip_id_high == 0x30))
> > +   return 1;
> > +
> > +   return 0;
> > +}
> > +
> > +static void ps8640_show_mcu_fw_version(struct ps8640 *ps_bridge)
> > +{
> > +   struct i2c_client *client = ps_bridge->client;
> > +   u8 major_ver, minor_ver;
> > +
> > +   ps8640_regr(client, ps_bridge->base_reg + 5, 0x4, _ver);
> > +   ps8640_regr(client, ps_bridge->base_reg + 5, 0x5, _ver);
> > +
> > +   DRM_INFO_ONCE("ps8640 rom fw version %d.%d\n", major_ver, minor_ver);
> > +}
> > +
> > +static int ps8640_bdg_enable(struct ps8640 *ps_bridge)
> > +{
> > +   struct i2c_client *client = ps_bridge->client;
> > +
> > +   if (ps8640_check_valid_id(ps_bridge)) {
> > +   ps8640_regw(client, ps_bridge->base_reg + 3, 0xfe, 0x13);
> > +   ps8640_regw(client, ps_bridge->base_reg + 3, 0xff, 0x18);
> > +   ps8640_regw(client, ps_bridge->base_reg + 3, 0xfe, 0x13);
> > +   ps8640_regw(client, ps_bridge->base_reg + 3, 0xff, 0x1c);

Can you introduce #defines with descriptive names for those magic
constants and register offsets, and maybe also i2c address offsets?

> > +
> > +   return 0;
> > +   }
> > +
> > +   return -1;

Never return -1 to signal a problem.
If there was an error, use a proper error code.

> > +}
> > +
> > +static void ps8640_prepare(struct ps8640 *ps_bridge)
> > +{
> > +   struct i2c_client *client = ps_bridge->client;
> > +   int err, retry_cnt = 0;
> > +   u8 set_vdo_done;
> > +
> > +   if (ps_bridge->enabled)
> > +   return;
> > +
> > +   if (drm_panel_prepare(ps_bridge->panel)) {
> > +   DRM_ERROR("failed to prepare panel\n");
> > +   return;
> > +   }
> > +
> > +   err = regulator_enable(ps_bridge->pwr_1v2_supply);
> > +   if (err < 0) {
> > +   DRM_ERROR("failed to enable pwr_1v2_supply: %d\n", err);

Missing panel unprepare.

> > +   return;
> > +   }
> > +
> > +   err = regulator_enable(ps_bridge->pwr_3v3_supply);
> > +   if (err < 0) {
> > +   DRM_ERROR("failed to enable pwr_3v3_supply: %d\n", err);

Missing panel unprepare and vdd12 regulator disable.

> > +   return;
> > +   }
> > +
> > +   gpiod_set_value(ps_bridge->gpio_slp_n, 1);
> > +   gpiod_set_value(ps_bridge->gpio_rst_n, 0);
> > +   usleep_range(500, 700);
> > +   gpiod_set_value(ps_bridge->gpio_rst_n, 1);
> > +
> > +   do {
> > +   msleep(50);
> > +   ps8640_regr(client, ps_bridge->base_reg + 2, PAGE2_GPIO_H,
> > +   _vdo_done);
> > +   } while ((retry_cnt++ < 70) && ((set_vdo_done & PS_GPIO9) != PS_GPIO9));
> > +
> > +   ps8640_show_mcu_fw_version(ps_bridge);
> > +   ps_bridge->enabled = true;
> > +}
> > +
> > +static void ps8640_pre_enable(struct drm_bridge *bridge)
> > +{
> > +   struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
> > +
> > +   ps8640_prepare(ps_bridge);
> > +}
> > +
> > +static void ps8640_enable(struct drm_bridge *bridge)
> > +{
> > +   struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
> > +
> > +   ps8640_bdg_enable(ps_bridge);
> > +
> > +   if (drm_panel_enable(ps_bridge->panel)) {
> > +   DRM_ERROR("failed to enable panel\n");
> > +   return;

The return is superfluous.

> > +   }
> > +}
> > +
> > +static void ps8640_disable(struct drm_bridge *bridge)
> > +{
> > +   struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
> > +
> > +   if (!ps_bridge->enabled)
> > +   return;
> > +
> > +   ps_bridge->enabled = false;
> > +
> > +   if (drm_panel_disable(ps_bridge->panel)) {
> > +   DRM_ERROR("failed to disable panel\n");
> > +   return;

Shouldn't we still disable the bridge, even if panel disable fails?

> > +   }
> > +
> > +   regulator_disable(ps_bridge->pwr_1v2_supply);
> > +   regulator_disable(ps_bridge->pwr_3v3_supply);
> > +   gpiod_set_value(ps_bridge->gpio_rst_n, 0);
> > +   gpiod_set_value(ps_bridge->gpio_slp_n, 0);
> > +}
> > +
> > +static void ps8640_post_disable(struct drm_bridge *bridge)
> > +{
> > +   struct ps8640 

Re: [RFC v2 2/2] drm/bridge: Add I2C based driver for ps8640 bridge

[jitao shi]

On Mon, 2015-11-02 at 10:09 +0800, Jitao Shi wrote:
> This patch adds drm_bridge driver for parade DSI to eDP bridge chip.
> 
> Signed-off-by: Jitao Shi 
---
changes since v1:
1. remove edid code
2. remove some wrong comments
3. tune some gpios name, make it easy understand the meaning
> ---
>  drivers/gpu/drm/bridge/Kconfig |9 +
>  drivers/gpu/drm/bridge/Makefile|1 +
>  drivers/gpu/drm/bridge/parade-ps8640.c |  479 
> 
>  3 files changed, 489 insertions(+)
>  create mode 100644 drivers/gpu/drm/bridge/parade-ps8640.c
> 
> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> index 2de52a5..8ecaeed 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -29,4 +29,13 @@ config DRM_PARADE_PS8622
>   ---help---
> Parade eDP-LVDS bridge chip driver.
>  
> +config DRM_PARADE_PS8640
> + bool "Parade PS8640 MIPI DSI to eDP Converter"
> + select DRM_KMS_HELPER
> + select DRM_PANEL
> + ---help---
> +   Choose this option if you have PS8640 for display
> +   The PS8640 is a high-performance and low-power
> +   MIPI DSI to eDP converter
> +
>  endmenu
> diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
> index e2eef1c..da9e4a4 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -3,3 +3,4 @@ ccflags-y := -Iinclude/drm
>  obj-$(CONFIG_DRM_DW_HDMI) += dw_hdmi.o
>  obj-$(CONFIG_DRM_NXP_PTN3460) += nxp-ptn3460.o
>  obj-$(CONFIG_DRM_PARADE_PS8622) += parade-ps8622.o
> +obj-$(CONFIG_DRM_PARADE_PS8640) += parade-ps8640.o
> diff --git a/drivers/gpu/drm/bridge/parade-ps8640.c 
> b/drivers/gpu/drm/bridge/parade-ps8640.c
> new file mode 100644
> index 000..52616ba
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/parade-ps8640.c
> @@ -0,0 +1,479 @@
> +/*
> + * Copyright (c) 2014 MediaTek Inc.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +
> +#define PAGE2_GPIO_L 0xa6
> +#define PAGE2_GPIO_H 0xa7
> +#define PS_GPIO9 BIT(1)
> +
> +#define PAGE4_REV_L  0xf0
> +#define PAGE4_REV_H  0xf1
> +#define PAGE4_CHIP_L 0xf2
> +#define PAGE4_CHIP_H 0xf3
> +
> +#define bridge_to_ps8640(e)  container_of(e, struct ps8640, bridge)
> +#define connector_to_ps8640(e)   container_of(e, struct ps8640, 
> connector)
> +
> +struct ps8640 {
> + struct drm_connector connector;
> + struct drm_bridge bridge;
> + struct i2c_client *client;
> + struct ps8640_driver_data *driver_data;
> + struct regulator *pwr_1v2_supply;
> + struct regulator *pwr_3v3_supply;
> + struct drm_panel *panel;
> + struct gpio_desc *gpio_rst_n;
> + struct gpio_desc *gpio_slp_n;
> + struct gpio_desc *gpio_mode_sel_n;
> + u16 base_reg;
> + bool enabled;
> +};
> +
> +static int ps8640_regr(struct i2c_client *client, u16 i2c_addr,
> +u8 reg, u8 *value)
> +{
> + int ret;
> +
> + client->addr = i2c_addr;
> +
> + ret = i2c_master_send(client, , 1);
> + if (ret <= 0) {
> + DRM_ERROR("Failed to send i2c command, ret=%d\n", ret);
> + return ret;
> + }
> +
> + ret = i2c_master_recv(client, value, 1);
> + if (ret <= 0) {
> + DRM_ERROR("Failed to recv i2c data, ret=%d\n", ret);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int ps8640_regw(struct i2c_client *client, u16 i2c_addr,
> +u8 reg, u8 value)
> +{
> + int ret;
> + char buf[2];
> +
> + client->addr = i2c_addr;
> +
> + buf[0] = reg;
> + buf[1] = value;
> + ret = i2c_master_send(client, buf, ARRAY_SIZE(buf));
> + if (ret <= 0) {
> + DRM_ERROR("Failed to send i2c command, ret=%d\n", ret);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int ps8640_check_valid_id(struct ps8640 *ps_bridge)
> +{
> + struct i2c_client *client = ps_bridge->client;
> + u8 rev_id_low, rev_id_high, chip_id_low, chip_id_high;
> + int retry_cnt = 0;
> +
> + do {
> + ps8640_regr(client, ps_bridge->base_reg + 4, PAGE4_CHIP_H,
> + _id_high);
> + if (chip_id_high != 0x30)
> + DRM_INFO("chip_id_high = 0x%x\n", chip_id_high);
> + } while ((retry_cnt++ < 2) && (chip_id_high != 

Re: [RFC v2 2/2] drm/bridge: Add I2C based driver for ps8640 bridge

[jitao shi]

On Mon, 2015-11-02 at 10:09 +0800, Jitao Shi wrote:
> This patch adds drm_bridge driver for parade DSI to eDP bridge chip.
> 
> Signed-off-by: Jitao Shi 
---
changes since v1:
1. remove edid code
2. remove some wrong comments
3. tune some gpios name, make it easy understand the meaning
> ---
>  drivers/gpu/drm/bridge/Kconfig |9 +
>  drivers/gpu/drm/bridge/Makefile|1 +
>  drivers/gpu/drm/bridge/parade-ps8640.c |  479 
> 
>  3 files changed, 489 insertions(+)
>  create mode 100644 drivers/gpu/drm/bridge/parade-ps8640.c
> 
> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> index 2de52a5..8ecaeed 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -29,4 +29,13 @@ config DRM_PARADE_PS8622
>   ---help---
> Parade eDP-LVDS bridge chip driver.
>  
> +config DRM_PARADE_PS8640
> + bool "Parade PS8640 MIPI DSI to eDP Converter"
> + select DRM_KMS_HELPER
> + select DRM_PANEL
> + ---help---
> +   Choose this option if you have PS8640 for display
> +   The PS8640 is a high-performance and low-power
> +   MIPI DSI to eDP converter
> +
>  endmenu
> diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
> index e2eef1c..da9e4a4 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -3,3 +3,4 @@ ccflags-y := -Iinclude/drm
>  obj-$(CONFIG_DRM_DW_HDMI) += dw_hdmi.o
>  obj-$(CONFIG_DRM_NXP_PTN3460) += nxp-ptn3460.o
>  obj-$(CONFIG_DRM_PARADE_PS8622) += parade-ps8622.o
> +obj-$(CONFIG_DRM_PARADE_PS8640) += parade-ps8640.o
> diff --git a/drivers/gpu/drm/bridge/parade-ps8640.c 
> b/drivers/gpu/drm/bridge/parade-ps8640.c
> new file mode 100644
> index 000..52616ba
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/parade-ps8640.c
> @@ -0,0 +1,479 @@
> +/*
> + * Copyright (c) 2014 MediaTek Inc.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +
> +#define PAGE2_GPIO_L 0xa6
> +#define PAGE2_GPIO_H 0xa7
> +#define PS_GPIO9 BIT(1)
> +
> +#define PAGE4_REV_L  0xf0
> +#define PAGE4_REV_H  0xf1
> +#define PAGE4_CHIP_L 0xf2
> +#define PAGE4_CHIP_H 0xf3
> +
> +#define bridge_to_ps8640(e)  container_of(e, struct ps8640, bridge)
> +#define connector_to_ps8640(e)   container_of(e, struct ps8640, 
> connector)
> +
> +struct ps8640 {
> + struct drm_connector connector;
> + struct drm_bridge bridge;
> + struct i2c_client *client;
> + struct ps8640_driver_data *driver_data;
> + struct regulator *pwr_1v2_supply;
> + struct regulator *pwr_3v3_supply;
> + struct drm_panel *panel;
> + struct gpio_desc *gpio_rst_n;
> + struct gpio_desc *gpio_slp_n;
> + struct gpio_desc *gpio_mode_sel_n;
> + u16 base_reg;
> + bool enabled;
> +};
> +
> +static int ps8640_regr(struct i2c_client *client, u16 i2c_addr,
> +u8 reg, u8 *value)
> +{
> + int ret;
> +
> + client->addr = i2c_addr;
> +
> + ret = i2c_master_send(client, , 1);
> + if (ret <= 0) {
> + DRM_ERROR("Failed to send i2c command, ret=%d\n", ret);
> + return ret;
> + }
> +
> + ret = i2c_master_recv(client, value, 1);
> + if (ret <= 0) {
> + DRM_ERROR("Failed to recv i2c data, ret=%d\n", ret);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int ps8640_regw(struct i2c_client *client, u16 i2c_addr,
> +u8 reg, u8 value)
> +{
> + int ret;
> + char buf[2];
> +
> + client->addr = i2c_addr;
> +
> + buf[0] = reg;
> + buf[1] = value;
> + ret = i2c_master_send(client, buf, ARRAY_SIZE(buf));
> + if (ret <= 0) {
> + DRM_ERROR("Failed to send i2c command, ret=%d\n", ret);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int ps8640_check_valid_id(struct ps8640 *ps_bridge)
> +{
> + struct i2c_client *client = ps_bridge->client;
> + u8 rev_id_low, rev_id_high, chip_id_low, chip_id_high;
> + int retry_cnt = 0;
> +
> + do {
> + ps8640_regr(client, ps_bridge->base_reg + 4, PAGE4_CHIP_H,
> + _id_high);
> + if (chip_id_high != 0x30)
> + DRM_INFO("chip_id_high = 0x%x\n", chip_id_high);
> + } while ((retry_cnt++ < 2)