[PATCH v4 1/3] drm/loongson: Add DRM Driver for Loongson 7A1000 bridge chip
Sam Ravnborg
sam at ravnborg.org
Wed Aug 4 21:12:27 UTC 2021
Hi Chenyang,
some feedback in the following.
I will try to find more time for review during the week.
Hi Thomas,
please see my question near drm_gem_vram_of_gem().
Sam
On Fri, Jul 30, 2021 at 05:41:46PM +0800, lichenyang wrote:
> From: Chenyang Li <lichenyang at loongson.cn>
>
> This patch adds an initial DRM driver for the Loongson LS7A1000
> bridge chip(LS7A). The LS7A bridge chip contains two display
> controllers, support dual display output. The maximum support for
> each channel display is to 1920x1080 at 60Hz.
> At present, DC device detection and DRM driver registration are
> completed, the crtc/plane/encoder/connector objects has been
> implemented.
> On Loongson 3A4000 CPU and 7A1000 system, we have achieved the use
> of dual screen, and support dual screen clone mode and expansion
> mode.
>
> v10:
> - Replace the drmm_ version functions.
> - Replace the simple_encoder version function.
> - Alphabetize file names.
>
> v9:
> - Optimize the error handling process.
> - Remove the useless flags parameter.
> - Fix some incorrect use of variables and constructs.
>
> v8:
> - Update the atomic_update function interface.
>
> v7:
> - The pixel clock is limited to less than 173000.
>
> v6:
> - Remove spin_lock in mmio reg read and write.
> - TO_UNCAC is replac with ioremap.
> - Fix error arguments in crtc_atomic_enable/disable/mode_valid.
>
> v5:
> - Change the name of the chip to LS7A.
> - Change magic value in crtc to macros.
> - Correct mistakes words.
> - Change the register operation function prefix to ls7a.
>
> v4:
> - Move the mode_valid function to the crtc.
>
> v3:
> - Move the mode_valid function to the connector and optimize it.
> - Fix num_crtc calculation method.
>
> v2:
> - Complete the case of 32-bit color in CRTC.
>
> Signed-off-by: Chenyang Li <lichenyang at loongson.cn>
> ---
> drivers/gpu/drm/Kconfig | 2 +
> drivers/gpu/drm/Makefile | 1 +
> drivers/gpu/drm/loongson/Kconfig | 14 +
> drivers/gpu/drm/loongson/Makefile | 14 +
> drivers/gpu/drm/loongson/loongson_connector.c | 47 +++
> drivers/gpu/drm/loongson/loongson_crtc.c | 238 +++++++++++++++
> drivers/gpu/drm/loongson/loongson_device.c | 35 +++
> drivers/gpu/drm/loongson/loongson_drv.c | 271 ++++++++++++++++++
> drivers/gpu/drm/loongson/loongson_drv.h | 149 ++++++++++
> drivers/gpu/drm/loongson/loongson_encoder.c | 21 ++
> drivers/gpu/drm/loongson/loongson_plane.c | 92 ++++++
> 11 files changed, 884 insertions(+)
> create mode 100644 drivers/gpu/drm/loongson/Kconfig
> create mode 100644 drivers/gpu/drm/loongson/Makefile
> create mode 100644 drivers/gpu/drm/loongson/loongson_connector.c
> create mode 100644 drivers/gpu/drm/loongson/loongson_crtc.c
> create mode 100644 drivers/gpu/drm/loongson/loongson_device.c
> create mode 100644 drivers/gpu/drm/loongson/loongson_drv.c
> create mode 100644 drivers/gpu/drm/loongson/loongson_drv.h
> create mode 100644 drivers/gpu/drm/loongson/loongson_encoder.c
> create mode 100644 drivers/gpu/drm/loongson/loongson_plane.c
>
> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> index 7ff89690a976..08562d9be6e3 100644
> --- a/drivers/gpu/drm/Kconfig
> +++ b/drivers/gpu/drm/Kconfig
> @@ -365,6 +365,8 @@ source "drivers/gpu/drm/xen/Kconfig"
>
> source "drivers/gpu/drm/vboxvideo/Kconfig"
>
> +source "drivers/gpu/drm/loongson/Kconfig"
> +
> source "drivers/gpu/drm/lima/Kconfig"
Preferably in alphabetical order, so after lima.
>
> source "drivers/gpu/drm/panfrost/Kconfig"
> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> index a118692a6df7..29c05b8cf2ad 100644
> --- a/drivers/gpu/drm/Makefile
> +++ b/drivers/gpu/drm/Makefile
> @@ -119,6 +119,7 @@ obj-$(CONFIG_DRM_PL111) += pl111/
> obj-$(CONFIG_DRM_TVE200) += tve200/
> obj-$(CONFIG_DRM_XEN) += xen/
> obj-$(CONFIG_DRM_VBOXVIDEO) += vboxvideo/
> +obj-$(CONFIG_DRM_LOONGSON) += loongson/
> obj-$(CONFIG_DRM_LIMA) += lima/
Likewise, after lima
> obj-$(CONFIG_DRM_PANFROST) += panfrost/
> obj-$(CONFIG_DRM_ASPEED_GFX) += aspeed/
> diff --git a/drivers/gpu/drm/loongson/Kconfig b/drivers/gpu/drm/loongson/Kconfig
> new file mode 100644
> index 000000000000..3cf42a4cca08
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/Kconfig
> @@ -0,0 +1,14 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +
> +config DRM_LOONGSON
> + tristate "DRM support for LS7A bridge chipset"
> + depends on DRM && PCI
> + depends on CPU_LOONGSON64
Maybe add || COMPILE_TEST - so we get better build coverage.
You risk we miss this driver when we do refactoring, if we cannot build
it using an allmodconfig for example.
> + select DRM_KMS_HELPER
> + select DRM_VRAM_HELPER
> + select DRM_TTM
> + select DRM_TTM_HELPER
Please verify that they are all needed.
There are no hits on "ttm" in the code, so the the two TTM symbols is
likely wrong.
> + default n
Drop this. n is default.
> + help
> + Support the display controllers found on the Loongson LS7A
> + bridge.
Consider adding a little more info here. For example the module name.
> diff --git a/drivers/gpu/drm/loongson/Makefile b/drivers/gpu/drm/loongson/Makefile
> new file mode 100644
> index 000000000000..d73ad44fe1d5
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/Makefile
> @@ -0,0 +1,14 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +#
> +# Makefile for loongson drm drivers.
> +# This driver provides support for the
> +# Direct Rendering Infrastructure (DRI)
> +
> +ccflags-y := -Iinclude/drm
Drop, this is not needed.
> +loongson-y := loongson_connector.o \
> + loongson_crtc.o \
> + loongson_device.o \
> + loongson_drv.o \
> + loongson_encoder.o \
> + loongson_plane.o
> +obj-$(CONFIG_DRM_LOONGSON) += loongson.o
> diff --git a/drivers/gpu/drm/loongson/loongson_connector.c b/drivers/gpu/drm/loongson/loongson_connector.c
> new file mode 100644
> index 000000000000..a4762d8f9987
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/loongson_connector.c
> @@ -0,0 +1,47 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +
> +#include "loongson_drv.h"
> +
> +static int loongson_get_modes(struct drm_connector *connector)
> +{
> + int count;
> +
> + count = drm_add_modes_noedid(connector, 1920, 1080);
> + drm_set_preferred_mode(connector, 1024, 768);
> +
> + return count;
> +}
> +
> +static const struct drm_connector_helper_funcs loongson_connector_helper = {
> + .get_modes = loongson_get_modes,
> +};
> +
> +static const struct drm_connector_funcs loongson_connector_funcs = {
> + .fill_modes = drm_helper_probe_single_connector_modes,
> + .destroy = drm_connector_cleanup,
> + .reset = drm_atomic_helper_connector_reset,
> + .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
> + .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> +};
> +
> +int loongson_connector_init(struct loongson_device *ldev, int index)
> +{
> + struct drm_device *dev = &ldev->dev;
> + struct drm_connector *connector;
> + struct loongson_connector *lconnector;
> +
> + lconnector = kzalloc(sizeof(struct loongson_connector), GFP_KERNEL);
> + if (!lconnector)
> + return -ENOMEM;
> +
> + lconnector->ldev = ldev;
> + lconnector->id = index;
> +
> + ldev->mode_info[index].connector = lconnector;
> + connector = &lconnector->base;
> + drm_connector_init(dev, connector, &loongson_connector_funcs,
> + DRM_MODE_CONNECTOR_Unknown);
> + drm_connector_helper_add(connector, &loongson_connector_helper);
> +
> + return 0;
> +}
As already said in another mail - convert the i2c to a brige and then
use the drm_bridge_connector - this is a more standard solution today.
And the connector needs to be specified, but it can come via the device
tree and then be added as a chained bridge.
This will be simple when the i2c parts are a bridge.
> diff --git a/drivers/gpu/drm/loongson/loongson_crtc.c b/drivers/gpu/drm/loongson/loongson_crtc.c
> new file mode 100644
> index 000000000000..b9eee34deab2
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/loongson_crtc.c
> @@ -0,0 +1,238 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +
> +#include "loongson_drv.h"
> +
> +static void try_each_loopc(u32 clk, u32 pstdiv, u32 frefc,
> + struct pix_pll *pll_config)
> +{
> + u32 loopc;
> + u32 clk_out;
> + u32 precision;
> + u32 min = 1000;
> + u32 base_clk = 100000L;
> +
> + for (loopc = LOOPC_MIN; loopc < LOOPC_MAX; loopc++) {
> + if ((loopc < FRE_REF_MIN * frefc) ||
> + (loopc > FRE_REF_MAX * frefc))
> + continue;
> +
> + clk_out = base_clk * loopc / frefc;
> + precision = (clk > clk_out) ? (clk - clk_out) : (clk_out - clk);
> + if (precision < min) {
> + pll_config->l2_div = pstdiv;
> + pll_config->l1_loopc = loopc;
> + pll_config->l1_frefc = frefc;
> + }
This looks very inefficient, as you may have several writes to
pll_config.
> + }
> +}
> +
> +static void cal_freq(u32 pixclock, struct pix_pll *pll_config)
> +{
> + u32 pstdiv;
> + u32 frefc;
> + u32 clk;
> +
> + for (pstdiv = 1; pstdiv < PST_DIV_MAX; pstdiv++) {
> + clk = pixclock * pstdiv;
> + for (frefc = DIV_REF_MIN; frefc <= DIV_REF_MAX; frefc++)
> + try_each_loopc(clk, pstdiv, frefc, pll_config);
> + }
> +}
So you call the inefficient loop in try_each_loopc in another loop.
I hope it is possible to re-think this - as it looks very inefficient.
Maybe it is needed to be like this, in which case you can just ignore my
comments.
> +
> +static void config_pll(struct loongson_device *ldev, unsigned long pll_base,
> + struct pix_pll *pll_cfg)
> +{
> + u32 val;
> + u32 count = 0;
> +
> + /* clear sel_pll_out0 */
> + val = ls7a_io_rreg(ldev, pll_base + 0x4);
> + val &= ~(1UL << 8);
> + ls7a_io_wreg(ldev, pll_base + 0x4, val);
Any change for proper defines for all these hardcoded numbers?
That may help a little with the readability.
> +
> + /* set pll_pd */
> + val = ls7a_io_rreg(ldev, pll_base + 0x4);
> + val |= (1UL << 13);
> + ls7a_io_wreg(ldev, pll_base + 0x4, val);
> +
> + /* clear set_pll_param */
> + val = ls7a_io_rreg(ldev, pll_base + 0x4);
> + val &= ~(1UL << 11);
> + ls7a_io_wreg(ldev, pll_base + 0x4, val);
> +
> + /* clear old value & config new value */
> + val = ls7a_io_rreg(ldev, pll_base + 0x4);
> + val &= ~(0x7fUL << 0);
> + val |= (pll_cfg->l1_frefc << 0); /* refc */
> + ls7a_io_wreg(ldev, pll_base + 0x4, val);
> + val = ls7a_io_rreg(ldev, pll_base + 0x0);
> + val &= ~(0x7fUL << 0);
> + val |= (pll_cfg->l2_div << 0); /* div */
> + val &= ~(0x1ffUL << 21);
> + val |= (pll_cfg->l1_loopc << 21); /* loopc */
> + ls7a_io_wreg(ldev, pll_base + 0x0, val);
> +
> + /* set set_pll_param */
> + val = ls7a_io_rreg(ldev, pll_base + 0x4);
> + val |= (1UL << 11);
> + ls7a_io_wreg(ldev, pll_base + 0x4, val);
> + /* clear pll_pd */
> + val = ls7a_io_rreg(ldev, pll_base + 0x4);
> + val &= ~(1UL << 13);
> + ls7a_io_wreg(ldev, pll_base + 0x4, val);
> +
> + while (!(ls7a_io_rreg(ldev, pll_base + 0x4) & 0x80)) {
> + cpu_relax();
> + count++;
> + if (count >= 1000) {
> + drm_err(&ldev->dev, "loongson-7A PLL lock failed\n");
> + break;
> + }
> + }
> +
> + val = ls7a_io_rreg(ldev, pll_base + 0x4);
> + val |= (1UL << 8);
> + ls7a_io_wreg(ldev, pll_base + 0x4, val);
> +}
> +
> +static void loongson_crtc_mode_set_nofb(struct drm_crtc *crtc)
> +{
> + struct drm_device *dev = crtc->dev;
> + struct loongson_device *ldev = to_loongson_device(dev);
> + struct loongson_crtc *lcrtc = to_loongson_crtc(crtc);
> + struct drm_display_mode *mode = &crtc->state->adjusted_mode;
> + const struct drm_format_info *format;
> + struct pix_pll pll_cfg;
> + u32 hr, hss, hse, hfl;
> + u32 vr, vss, vse, vfl;
> + u32 pix_freq;
> + u32 reg_offset;
> +
> + hr = mode->hdisplay;
> + hss = mode->hsync_start;
> + hse = mode->hsync_end;
> + hfl = mode->htotal;
> +
> + vr = mode->vdisplay;
> + vss = mode->vsync_start;
> + vse = mode->vsync_end;
> + vfl = mode->vtotal;
> +
> + pix_freq = mode->clock;
> + reg_offset = lcrtc->reg_offset;
> + format = crtc->primary->state->fb->format;
> +
> + ls7a_mm_wreg(ldev, FB_DITCFG_REG + reg_offset, 0);
> + ls7a_mm_wreg(ldev, FB_DITTAB_LO_REG + reg_offset, 0);
> + ls7a_mm_wreg(ldev, FB_DITTAB_HI_REG + reg_offset, 0);
> + ls7a_mm_wreg(ldev, FB_PANCFG_REG + reg_offset, FB_PANCFG_DEF);
> + ls7a_mm_wreg(ldev, FB_PANTIM_REG + reg_offset, 0);
> +
> + ls7a_mm_wreg(ldev, FB_HDISPLAY_REG + reg_offset, (hfl << 16) | hr);
> + ls7a_mm_wreg(ldev, FB_HSYNC_REG + reg_offset,
> + FB_HSYNC_PULSE | (hse << 16) | hss);
> +
> + ls7a_mm_wreg(ldev, FB_VDISPLAY_REG + reg_offset, (vfl << 16) | vr);
> + ls7a_mm_wreg(ldev, FB_VSYNC_REG + reg_offset,
> + FB_VSYNC_PULSE | (vse << 16) | vss);
> +
> + switch (format->format) {
> + case DRM_FORMAT_RGB565:
> + lcrtc->cfg_reg |= 0x3;
> + break;
> + case DRM_FORMAT_RGB888:
> + case DRM_FORMAT_XRGB8888:
> + case DRM_FORMAT_ARGB8888:
> + default:
> + lcrtc->cfg_reg |= 0x4;
> + break;
> + }
As a general rule - an empty line after a closing brace.
> + ls7a_mm_wreg(ldev, FB_CFG_REG + reg_offset, lcrtc->cfg_reg);
> +
> + cal_freq(pix_freq, &pll_cfg);
> + config_pll(ldev, LS7A_PIX_PLL + reg_offset, &pll_cfg);
> +}
> +
> +static void loongson_crtc_atomic_enable(struct drm_crtc *crtc,
> + struct drm_atomic_state *old_state)
> +{
> + struct drm_device *dev = crtc->dev;
> + struct loongson_device *ldev = to_loongson_device(dev);
> + struct loongson_crtc *lcrtc = to_loongson_crtc(crtc);
> + u32 reg_offset = lcrtc->reg_offset;
> +
> + lcrtc->cfg_reg |= CFG_ENABLE;
> + ls7a_mm_wreg(ldev, FB_CFG_REG + reg_offset, lcrtc->cfg_reg);
> +}
> +
> +static void loongson_crtc_atomic_disable(struct drm_crtc *crtc,
> + struct drm_atomic_state *old_state)
> +{
> + struct drm_device *dev = crtc->dev;
> + struct loongson_device *ldev = to_loongson_device(dev);
> + struct loongson_crtc *lcrtc = to_loongson_crtc(crtc);
> + u32 reg_offset = lcrtc->reg_offset;
> +
> + lcrtc->cfg_reg &= ~CFG_ENABLE;
> + ls7a_mm_wreg(ldev, FB_CFG_REG + reg_offset, lcrtc->cfg_reg);
> +}
> +
> +static enum drm_mode_status loongson_mode_valid(struct drm_crtc *crtc,
> + const struct drm_display_mode *mode)
> +{
> + if (mode->hdisplay > 1920)
> + return MODE_BAD;
> + if (mode->vdisplay > 1080)
> + return MODE_BAD;
> + if (mode->hdisplay % 64)
> + return MODE_BAD;
> + if (mode->clock >= 173000)
> + return MODE_CLOCK_HIGH;
> +
> + return MODE_OK;
> +}
> +
> +static const struct drm_crtc_helper_funcs loongson_crtc_helper_funcs = {
> + .mode_valid = loongson_mode_valid,
> + .atomic_enable = loongson_crtc_atomic_enable,
> + .atomic_disable = loongson_crtc_atomic_disable,
> + .mode_set_nofb = loongson_crtc_mode_set_nofb,
> +};
> +
> +static const struct drm_crtc_funcs loongson_crtc_funcs = {
> + .set_config = drm_atomic_helper_set_config,
> + .page_flip = drm_atomic_helper_page_flip,
> + .reset = drm_atomic_helper_crtc_reset,
> + .atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
> + .atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
> +};
> +
> +int loongson_crtc_init(struct loongson_device *ldev, int index)
> +{
> + struct drm_device *dev = &ldev->dev;
> + struct loongson_plane *plane;
> + struct loongson_crtc *lcrtc;
> +
> + plane = loongson_plane_init(dev, index);
> + if (IS_ERR(plane))
> + return PTR_ERR(plane);
> +
> + lcrtc = drmm_crtc_alloc_with_planes(dev, struct loongson_crtc, base,
> + &plane->base, NULL,
> + &loongson_crtc_funcs, NULL);
> + if (IS_ERR(lcrtc))
> + return PTR_ERR(lcrtc);
> +
> + lcrtc->ldev = ldev;
> + lcrtc->reg_offset = index * REG_OFFSET;
> + lcrtc->cfg_reg = CFG_RESET;
> + lcrtc->crtc_id = index;
> + lcrtc->plane = plane;
> +
> + drm_crtc_helper_add(&lcrtc->base, &loongson_crtc_helper_funcs);
> +
> + ldev->mode_info[index].crtc = lcrtc;
> +
> + return 0;
> +}
> +
> diff --git a/drivers/gpu/drm/loongson/loongson_device.c b/drivers/gpu/drm/loongson/loongson_device.c
> new file mode 100644
> index 000000000000..a79d64fc1a06
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/loongson_device.c
> @@ -0,0 +1,35 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +
> +#include "loongson_drv.h"
> +
> +u32 loongson_gpu_offset(struct drm_plane_state *state,
> + struct loongson_device *ldev)
> +{
> + struct drm_gem_vram_object *gbo;
> + u32 gpu_addr;
> +
> + gbo = drm_gem_vram_of_gem(state->fb->obj[0]);
> + gpu_addr = ldev->vram_start + drm_gem_vram_offset(gbo);
@Thomas Zimmermann - can this be improved?
> +
> + return gpu_addr;
> +}
> +
Have you considered to use regmap for all these register access.
It looks like the correct abstraction to use here.
> +u32 ls7a_io_rreg(struct loongson_device *ldev, u32 offset)
> +{
> + return readl(ldev->io + offset);
> +}
> +
> +void ls7a_io_wreg(struct loongson_device *ldev, u32 offset, u32 val)
> +{
> + writel(val, ldev->io + offset);
> +}
> +
And another regmap for these.
> +u32 ls7a_mm_rreg(struct loongson_device *ldev, u32 offset)
> +{
> + return readl(ldev->mmio + offset);
> +}
> +
> +void ls7a_mm_wreg(struct loongson_device *ldev, u32 offset, u32 val)
> +{
> + writel(val, ldev->mmio + offset);
> +}
> diff --git a/drivers/gpu/drm/loongson/loongson_drv.c b/drivers/gpu/drm/loongson/loongson_drv.c
> new file mode 100644
> index 000000000000..2224a03adc1a
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/loongson_drv.c
> @@ -0,0 +1,271 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Loongson LS7A1000 bridge chipset drm driver
> + */
> +
> +#include <linux/console.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/pci.h>
> +
> +#include "loongson_drv.h"
> +
> +/* Interface history:
> + * 0.1 - original.
> + */
> +#define DRIVER_MAJOR 0
> +#define DRIVER_MINOR 1
> +
> +static const struct drm_mode_config_funcs loongson_mode_funcs = {
> + .fb_create = drm_gem_fb_create,
> + .atomic_check = drm_atomic_helper_check,
> + .atomic_commit = drm_atomic_helper_commit,
> + .output_poll_changed = drm_fb_helper_output_poll_changed,
> + .mode_valid = drm_vram_helper_mode_valid
> +};
> +
> +static int loongson_device_init(struct drm_device *dev)
> +{
> + struct loongson_device *ldev = to_loongson_device(dev);
> + struct pci_dev *pdev = to_pci_dev(dev->dev);
> + struct pci_dev *gpu_pdev;
> + resource_size_t aper_base;
> + resource_size_t aper_size;
> + resource_size_t mmio_base;
> + resource_size_t mmio_size;
> + int ret;
> +
> + /* GPU MEM */
> + /* We need get 7A-gpu pci device information for ldev->gpu_pdev */
> + /* dev->pdev save 7A-dc pci device information */
> + gpu_pdev = pci_get_device(PCI_VENDOR_ID_LOONGSON,
> + PCI_DEVICE_ID_LOONGSON_GPU, NULL);
> + ret = pci_enable_device(gpu_pdev);
Consider to use pcim_enable_device - you get come cleanup for free then.
> + if (ret)
> + return ret;
> + pci_set_drvdata(gpu_pdev, dev);
> +
> + aper_base = pci_resource_start(gpu_pdev, 2);
> + aper_size = pci_resource_len(gpu_pdev, 2);
> + ldev->vram_start = aper_base;
> + ldev->vram_size = aper_size;
> +
> + if (!devm_request_mem_region(dev->dev, ldev->vram_start,
> + ldev->vram_size, "loongson_vram")) {
> + drm_err(dev, "Can't reserve VRAM\n");
> + return -ENXIO;
> + }
> +
> + /* DC MEM */
> + mmio_base = pci_resource_start(pdev, 0);
> + mmio_size = pci_resource_len(pdev, 0);
> + ldev->mmio = devm_ioremap(dev->dev, mmio_base, mmio_size);
> + if (!ldev->mmio) {
> + drm_err(dev, "Cannot map mmio region\n");
> + return -ENOMEM;
> + }
> +
> + if (!devm_request_mem_region(dev->dev, mmio_base,
> + mmio_size, "loongson_mmio")) {
> + drm_err(dev, "Can't reserve mmio registers\n");
> + return -ENOMEM;
> + }
> +
> + /* DC IO */
> + ldev->io = devm_ioremap(dev->dev, LS7A_CHIPCFG_REG_BASE, 0xf);
> + if (!ldev->io)
> + return -ENOMEM;
> +
> + drm_info(dev, "DC mmio base 0x%llx size 0x%llx io 0x%llx\n",
> + mmio_base, mmio_size, *(u64 *)ldev->io);
> + drm_info(dev, "GPU vram start = 0x%x size = 0x%x\n",
> + ldev->vram_start, ldev->vram_size);
> +
> + return 0;
> +}
> +
> +int loongson_modeset_init(struct loongson_device *ldev)
> +{
> + struct drm_encoder *encoder;
> + struct drm_connector *connector;
> + int i;
> + int ret;
> +
> + for (i = 0; i < 2; i++) {
Why 2 - could you use a constant here?
> + ret = loongson_crtc_init(ldev, i);
> + if (ret) {
> + drm_warn(&ldev->dev, "loongson crtc%d init fail\n", i);
> + continue;
> + }
> +
> + ret = loongson_encoder_init(ldev, i);
> + if (ret) {
> + drm_err(&ldev->dev, "loongson_encoder_init failed\n");
> + return ret;
> + }
> +
> + ret = loongson_connector_init(ldev, i);
> + if (ret) {
> + drm_err(&ldev->dev, "loongson_connector_init failed\n");
> + return ret;
> + }
> +
> + encoder = &ldev->mode_info[i].encoder->base;
> + connector = &ldev->mode_info[i].connector->base;
> + drm_connector_attach_encoder(connector, encoder);
> + ldev->num_crtc++;
> + }
> +
> + return 0;
> +}
> +
> +static int loongson_driver_init(struct drm_device *dev)
> +{
> + struct loongson_device *ldev = to_loongson_device(dev);
> + int ret;
> +
> + ret = loongson_device_init(dev);
> + if (ret)
> + goto err;
> +
> + ret = drmm_vram_helper_init(dev, ldev->vram_start, ldev->vram_size);
> + if (ret) {
> + drm_err(dev, "Error initializing vram %d\n", ret);
> + goto err;
> + }
> +
> + drm_mode_config_init(dev);
Fro mthe documntation:
* FIXME: This function is deprecated and drivers should be converted over to
* drmm_mode_config_init().
> + dev->mode_config.funcs = (void *)&loongson_mode_funcs;
> + dev->mode_config.min_width = 1;
> + dev->mode_config.min_height = 1;
> + dev->mode_config.max_width = 4096;
> + dev->mode_config.max_height = 4096;
> + dev->mode_config.preferred_depth = 32;
> + dev->mode_config.prefer_shadow = 1;
> + dev->mode_config.fb_base = ldev->vram_start;
> + dev->mode_config.allow_fb_modifiers = true;
> +
> + ret = loongson_modeset_init(ldev);
> + if (ret) {
> + drm_err(dev, "Fatal error during modeset init: %d\n", ret);
> + goto err;
> + }
> +
> + drm_kms_helper_poll_init(dev);
> + drm_mode_config_reset(dev);
> +
> + return 0;
> +
> +err:
> + drm_err(dev, "failed to initialize drm driver: %d\n", ret);
> + return ret;
> +}
> +
> +static void loongson_driver_fini(struct drm_device *dev)
> +{
> + drm_vram_helper_release_mm(dev);
I think this is not needed when you use drmm_vram_helper_init().
> + drm_mode_config_cleanup(dev);
Drop this when you use drmm_ variant.
> + dev->dev_private = NULL;
> + dev_set_drvdata(dev->dev, NULL);
> +}
> +
> +DEFINE_DRM_GEM_FOPS(fops);
> +
> +static struct drm_driver loongson_driver = {
> + .driver_features = DRIVER_MODESET | DRIVER_GEM | DRIVER_ATOMIC,
> + .fops = &fops,
> + DRM_GEM_VRAM_DRIVER,
> +
> + .name = DRIVER_NAME,
> + .desc = DRIVER_DESC,
> + .date = DRIVER_DATE,
> + .major = DRIVER_MAJOR,
> + .minor = DRIVER_MINOR,
> +};
> +
> +static int loongson_pci_probe(struct pci_dev *pdev,
> + const struct pci_device_id *ent)
> +{
> + struct loongson_device *ldev;
> + struct drm_device *dev;
> + int ret;
> +
> + DRM_INFO("Start loongson drm probe.\n");
> + ldev = devm_drm_dev_alloc(&pdev->dev, &loongson_driver,
> + struct loongson_device, dev);
This shoud use devm_drm_dev_alloc
See "Display driver example" in drm_drv.c
Following this example will fix a few things in the code below.
> + if (IS_ERR(ldev))
> + return PTR_ERR(ldev);
> +
> + dev = &ldev->dev;
> + pci_set_drvdata(pdev, dev);
> +
> + ret = pci_enable_device(pdev);
> + if (ret) {
> + drm_err(dev, "failed to enable pci device: %d\n", ret);
> + goto err_free;
> + }
> +
> + ret = loongson_driver_init(dev);
> + if (ret) {
> + drm_err(dev, "failed to load loongson: %d\n", ret);
> + goto err_pdev;
> + }
> +
> + ret = drm_dev_register(dev, 0);
> + if (ret) {
> + drm_err(dev, "failed to register drv for userspace access: %d\n",
> + ret);
> + goto driver_fini;
> + }
> +
> + drm_fbdev_generic_setup(dev, dev->mode_config.preferred_depth);
> + DRM_INFO("loongson fbdev enabled.\n");
> +
> + return 0;
> +
> +driver_fini:
> + loongson_driver_fini(dev);
> +err_pdev:
> + pci_disable_device(pdev);
> +err_free:
> + drm_dev_put(dev);
> + return ret;
> +}
> +
> +static void loongson_pci_remove(struct pci_dev *pdev)
> +{
> + struct drm_device *dev = pci_get_drvdata(pdev);
> +
> + drm_dev_unregister(dev);
> + loongson_driver_fini(dev);
> + drm_dev_put(dev);
Not needed when you use drmm infrastructure for allocating drm_device.
> +}
> +
> +static struct pci_device_id loongson_pci_devices[] = {
> + { PCI_DEVICE(PCI_VENDOR_ID_LOONGSON, PCI_DEVICE_ID_LOONGSON_DC) },
> + {0,}
> +};
> +
> +static struct pci_driver loongson_drm_pci_driver = {
> + .name = DRIVER_NAME,
> + .id_table = loongson_pci_devices,
> + .probe = loongson_pci_probe,
> + .remove = loongson_pci_remove,
> +};
> +
> +static int __init loongson_drm_init(void)
> +{
> + return pci_register_driver(&loongson_drm_pci_driver);
> +}
> +
> +static void __exit loongson_drm_exit(void)
> +{
> + pci_unregister_driver(&loongson_drm_pci_driver);
> +}
> +
> +module_init(loongson_drm_init);
> +module_exit(loongson_drm_exit);
> +
> +MODULE_AUTHOR(DRIVER_AUTHOR);
> +MODULE_DESCRIPTION(DRIVER_DESC);
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/gpu/drm/loongson/loongson_drv.h b/drivers/gpu/drm/loongson/loongson_drv.h
> new file mode 100644
> index 000000000000..75965d198212
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/loongson_drv.h
> @@ -0,0 +1,149 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +
> +#ifndef __LOONGSON_DRV_H__
> +#define __LOONGSON_DRV_H__
> +
> +#include <drm/drm_atomic.h>
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_connector.h>
> +#include <drm/drm_crtc.h>
> +#include <drm/drm_crtc_helper.h>
> +#include <drm/drm_drv.h>
> +#include <drm/drm_encoder.h>
> +#include <drm/drm_fb_helper.h>
> +#include <drm/drm_fourcc.h>
> +#include <drm/drm_gem.h>
> +#include <drm/drm_gem_framebuffer_helper.h>
> +#include <drm/drm_gem_vram_helper.h>
> +#include <drm/drm_probe_helper.h>
> +#include <drm/drm_plane.h>
> +#include <drm/drm_plane_helper.h>
The header file should only include the header file needed here.
.c file should include whatever else they need.
Also - use forward declaration as preference to including a header file.
> +
> +/* General customization:
> + */
> +#define DRIVER_AUTHOR "Loongson graphics driver team"
> +#define DRIVER_NAME "loongson-drm"
> +#define DRIVER_DESC "Loongson LS7A DRM driver"
> +#define DRIVER_DATE "20200915"
> +
> +#define to_loongson_crtc(x) container_of(x, struct loongson_crtc, base)
> +#define to_loongson_encoder(x) container_of(x, struct loongson_encoder, base)
> +
> +#define LS7A_CHIPCFG_REG_BASE (0x10010000)
> +#define PCI_DEVICE_ID_LOONGSON_DC 0x7a06
> +#define PCI_DEVICE_ID_LOONGSON_GPU 0x7a15
> +#define LS7A_PIX_PLL (0x04b0)
> +#define REG_OFFSET (0x10)
> +#define FB_CFG_REG (0x1240)
> +#define FB_ADDR0_REG (0x1260)
> +#define FB_ADDR1_REG (0x1580)
> +#define FB_STRI_REG (0x1280)
> +#define FB_DITCFG_REG (0x1360)
> +#define FB_DITTAB_LO_REG (0x1380)
> +#define FB_DITTAB_HI_REG (0x13a0)
> +#define FB_PANCFG_REG (0x13c0)
> +#define FB_PANTIM_REG (0x13e0)
> +#define FB_HDISPLAY_REG (0x1400)
> +#define FB_HSYNC_REG (0x1420)
> +#define FB_VDISPLAY_REG (0x1480)
> +#define FB_VSYNC_REG (0x14a0)
> +
> +#define CFG_FMT GENMASK(2, 0)
> +#define CFG_FBSWITCH BIT(7)
> +#define CFG_ENABLE BIT(8)
> +#define CFG_FBNUM BIT(11)
> +#define CFG_GAMMAR BIT(12)
> +#define CFG_RESET BIT(20)
> +
> +#define FB_PANCFG_DEF 0x80001311
> +#define FB_HSYNC_PULSE (1 << 30)
> +#define FB_VSYNC_PULSE (1 << 30)
> +
> +/* PIX PLL */
> +#define LOOPC_MIN 24
> +#define LOOPC_MAX 161
> +#define FRE_REF_MIN 12
> +#define FRE_REF_MAX 32
> +#define DIV_REF_MIN 3
> +#define DIV_REF_MAX 5
> +#define PST_DIV_MAX 64
> +
> +struct pix_pll {
> + u32 l2_div;
> + u32 l1_loopc;
> + u32 l1_frefc;
> +};
> +
> +struct loongson_crtc {
> + struct drm_crtc base;
> + struct loongson_device *ldev;
> + u32 crtc_id;
> + u32 reg_offset;
> + u32 cfg_reg;
> + struct loongson_plane *plane;
> +};
> +
> +struct loongson_plane {
> + struct drm_plane base;
> +};
> +
> +struct loongson_encoder {
> + struct drm_encoder base;
> + struct loongson_device *ldev;
> + struct loongson_crtc *lcrtc;
> +};
> +
> +struct loongson_connector {
> + struct drm_connector base;
> + struct loongson_device *ldev;
> + u16 id;
> + u32 type;
> +};
> +
> +struct loongson_mode_info {
> + struct loongson_device *ldev;
> + struct loongson_crtc *crtc;
> + struct loongson_encoder *encoder;
> + struct loongson_connector *connector;
> +};
> +
> +struct loongson_device {
> + struct drm_device dev;
> + struct drm_atomic_state *state;
> +
> + void __iomem *mmio;
> + void __iomem *io;
> + u32 vram_start;
> + u32 vram_size;
> +
> + u32 num_crtc;
> + struct loongson_mode_info mode_info[2];
> + struct pci_dev *gpu_pdev; /* LS7A gpu device info */
> +};
I did not check, but I think you can embed more into struct
loongson_device so data is allocated in less chunks.
And lifetime is easier to handle.
> +
> +static inline struct loongson_device *to_loongson_device(struct drm_device *dev)
> +{
> + return container_of(dev, struct loongson_device, dev);
> +}
> +
> +/* crtc */
> +int loongson_crtc_init(struct loongson_device *ldev, int index);
> +
> +/* connector */
> +int loongson_connector_init(struct loongson_device *ldev, int index);
> +
> +/* encoder */
> +int loongson_encoder_init(struct loongson_device *ldev, int index);
> +
> +/* plane */
> +struct loongson_plane *loongson_plane_init(struct drm_device *dev, int index);
> +
> +/* device */
> +u32 loongson_gpu_offset(struct drm_plane_state *state,
> + struct loongson_device *dev);
> +u32 ls7a_mm_rreg(struct loongson_device *ldev, u32 offset);
> +void ls7a_mm_wreg(struct loongson_device *ldev, u32 offset, u32 val);
> +u32 ls7a_io_rreg(struct loongson_device *ldev, u32 offset);
> +void ls7a_io_wreg(struct loongson_device *ldev, u32 offset, u32 val);
> +
> +#endif /* __LOONGSON_DRV_H__ */
> diff --git a/drivers/gpu/drm/loongson/loongson_encoder.c b/drivers/gpu/drm/loongson/loongson_encoder.c
> new file mode 100644
> index 000000000000..a6325cb261d4
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/loongson_encoder.c
> @@ -0,0 +1,21 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +
> +#include <drm/drm_simple_kms_helper.h>
> +
> +#include "loongson_drv.h"
> +
> +int loongson_encoder_init(struct loongson_device *ldev, int index)
> +{
> + struct drm_device *dev = &ldev->dev;
> + struct loongson_encoder *lencoder;
> +
> + lencoder = drmm_simple_encoder_alloc(dev, struct loongson_encoder,
> + base, DRM_MODE_ENCODER_DAC);
> + if (IS_ERR(lencoder))
> + return PTR_ERR(lencoder);
> +
> + lencoder->base.possible_crtcs = 1 << index;
> + ldev->mode_info[index].encoder = lencoder;
> +
> + return 0;
> +}
> diff --git a/drivers/gpu/drm/loongson/loongson_plane.c b/drivers/gpu/drm/loongson/loongson_plane.c
> new file mode 100644
> index 000000000000..b55b8d8628f0
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/loongson_plane.c
> @@ -0,0 +1,92 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +
> +#include "loongson_drv.h"
> +
> +static void loongson_plane_atomic_update(struct drm_plane *plane,
> + struct drm_atomic_state *state)
> +{
> + struct loongson_crtc *lcrtc;
> + struct loongson_device *ldev;
> + struct drm_plane_state *lstate = plane->state;
> + u32 gpu_addr = 0;
> + u32 fb_addr = 0;
> + u32 reg_val = 0;
> + u32 reg_offset;
> + u32 pitch;
> + u8 depth;
> + u32 x, y;
> +
> + if (!lstate->crtc || !lstate->fb)
> + return;
> +
> + pitch = lstate->fb->pitches[0];
> + lcrtc = to_loongson_crtc(lstate->crtc);
> + ldev = lcrtc->ldev;
> + reg_offset = lcrtc->reg_offset;
> + x = lstate->crtc->x;
> + y = lstate->crtc->y;
> + depth = lstate->fb->format->cpp[0] << 3;
> +
> + gpu_addr = loongson_gpu_offset(lstate, ldev);
> + reg_val = (pitch + 255) & ~255;
> + ls7a_mm_wreg(ldev, FB_STRI_REG + reg_offset, reg_val);
> +
> + switch (depth) {
> + case 12 ... 16:
> + fb_addr = gpu_addr + y * pitch + ALIGN(x, 64) * 2;
> + break;
> + case 24 ... 32:
> + default:
> + fb_addr = gpu_addr + y * pitch + ALIGN(x, 64) * 4;
> + break;
> + }
> +
> + ls7a_mm_wreg(ldev, FB_ADDR0_REG + reg_offset, fb_addr);
> + ls7a_mm_wreg(ldev, FB_ADDR1_REG + reg_offset, fb_addr);
> + reg_val = lcrtc->cfg_reg | CFG_ENABLE;
> + ls7a_mm_wreg(ldev, FB_CFG_REG + reg_offset, reg_val);
> +}
> +
> +static const uint32_t loongson_formats[] = {
> + DRM_FORMAT_RGB565,
> + DRM_FORMAT_RGB888,
> + DRM_FORMAT_XRGB8888,
> + DRM_FORMAT_ARGB8888,
> +};
> +
> +static const uint64_t loongson_format_modifiers[] = { DRM_FORMAT_MOD_LINEAR,
> + DRM_FORMAT_MOD_INVALID };
> +
> +static const struct drm_plane_funcs loongson_plane_funcs = {
> + .atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
> + .atomic_destroy_state = drm_atomic_helper_plane_destroy_state,
> + .disable_plane = drm_atomic_helper_disable_plane,
> + .reset = drm_atomic_helper_plane_reset,
> + .update_plane = drm_atomic_helper_update_plane,
> +};
> +
> +static const struct drm_plane_helper_funcs loongson_plane_helper_funcs = {
> + .prepare_fb = drm_gem_vram_plane_helper_prepare_fb,
> + .cleanup_fb = drm_gem_vram_plane_helper_cleanup_fb,
> + .atomic_update = loongson_plane_atomic_update,
> +};
> +
> +struct loongson_plane *loongson_plane_init(struct drm_device *dev, int index)
> +{
> + struct loongson_plane *plane;
> +
> + plane = drmm_universal_plane_alloc(dev, struct loongson_plane, base,
> + BIT(index), &loongson_plane_funcs,
> + loongson_formats,
> + ARRAY_SIZE(loongson_formats),
> + loongson_format_modifiers,
> + DRM_PLANE_TYPE_PRIMARY, NULL);
> + if (IS_ERR(plane)) {
> + drm_err(dev, "failed to allocate and initialize plane\n");
> + return plane;
> + }
> +
> + drm_plane_helper_add(&plane->base, &loongson_plane_helper_funcs);
> +
> + return plane;
> +}
> --
> 2.32.0
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