On Fri, Dec 15, 2017 at 2:59 AM, Oleksandr Shamray
[off-list ref] wrote:

Driver adds support of Aspeed 2500/2400 series SOC JTAG master controller.

Looks good. I have a few small things below, but I am happy to see
this merged from my point of view as ASPEED maintainer.

Cheers,

Joel

+
+menuconfig JTAG_ASPEED
+       tristate "Aspeed SoC JTAG controller support"
+       depends on JTAG && HAS_IOMEM

Add ARCH_ASPEED || COMPILE_TEST

+static int aspeed_jtag_xfer(struct jtag *jtag, struct jtag_xfer *xfer,
+                           u8 *xfer_data)
+{
+       static const u8 sm_update_shiftir[] = {1, 1, 0, 0};
+       static const u8 sm_update_shiftdr[] = {1, 0, 0};
+       static const u8 sm_pause_idle[] = {1, 1, 0};
+       static const u8 sm_pause_update[] = {1, 1};
+       struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
+       unsigned long *data = (unsigned long *)xfer_data;
+       unsigned long remain_xfer = xfer->length;
+       unsigned long offset;
+       char dbg_str[256];
+       int pos = 0;
+       int i;
+
+       for (offset = 0, i = 0; offset < xfer->length;
+                       offset += ASPEED_JTAG_DATA_CHUNK_SIZE, i++) {

It looks like offset is unused.

+               pos += snprintf(&dbg_str[pos], sizeof(dbg_str) - pos,
+                               "0x%08lx ", data[i]);
+       }
+
+       dev_dbg(aspeed_jtag->dev, "aspeed_jtag %s %s xfer, mode:%s, END:%d, len:%lu, TDI[%s]\n",
+               xfer->type == JTAG_SIR_XFER ? "SIR" : "SDR",
+               xfer->direction == JTAG_READ_XFER ? "READ" : "WRITE",
+               aspeed_jtag->mode & JTAG_XFER_HW_MODE ? "HW" : "SW",
+               xfer->endstate, remain_xfer, dbg_str);
+
+       if (!(aspeed_jtag->mode & JTAG_XFER_HW_MODE)) {
+               /* SW mode */
+               aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+                                 ASPEED_JTAG_SW_MODE_TDIO, ASPEED_JTAG_SW);
+
+               if (aspeed_jtag->status != JTAG_STATE_IDLE) {
+                       /*IR/DR Pause->Exit2 IR / DR->Update IR /DR */
+                       aspeed_jtag_sm_cycle(aspeed_jtag, sm_pause_update,
+                                            sizeof(sm_pause_update));
+               }
+
+               if (xfer->type == JTAG_SIR_XFER)
+                       /* ->IRSCan->CapIR->ShiftIR */
+                       aspeed_jtag_sm_cycle(aspeed_jtag, sm_update_shiftir,
+                                            sizeof(sm_update_shiftir));
+               else
+                       /* ->DRScan->DRCap->DRShift */
+                       aspeed_jtag_sm_cycle(aspeed_jtag, sm_update_shiftdr,
+                                            sizeof(sm_update_shiftdr));
+
+               aspeed_jtag_xfer_sw(aspeed_jtag, xfer, data);
+
+               /* DIPause/DRPause */
+               aspeed_jtag_tck_cycle(aspeed_jtag, 0, 0);
+
+               if (xfer->endstate == JTAG_STATE_IDLE) {
+                       /* ->DRExit2->DRUpdate->IDLE */
+                       aspeed_jtag_sm_cycle(aspeed_jtag, sm_pause_idle,
+                                            sizeof(sm_pause_idle));
+               }
+       } else {
+               /* hw mode */
+               aspeed_jtag_write(aspeed_jtag, 0, ASPEED_JTAG_SW);
+               aspeed_jtag_xfer_hw(aspeed_jtag, xfer, data);
+       }
+
+       aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+                         ASPEED_JTAG_SW_MODE_TDIO, ASPEED_JTAG_SW);
+       aspeed_jtag->status = xfer->endstate;
+       return 0;
+}

+
+static irqreturn_t aspeed_jtag_interrupt(s32 this_irq, void *dev_id)
+{
+       struct aspeed_jtag *aspeed_jtag = dev_id;
+       irqreturn_t ret;
+       u32 status;
+
+       status = aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_ISR);
+       dev_dbg(aspeed_jtag->dev, "status %x\n", status);
+
+       if (status & ASPEED_JTAG_ISR_INT_MASK) {
+               aspeed_jtag_write(aspeed_jtag,
+                                 (status & ASPEED_JTAG_ISR_INT_MASK)
+                                 | (status & ASPEED_JTAG_ISR_INT_EN_MASK),
+                                 ASPEED_JTAG_ISR);
+               aspeed_jtag->flag |= status & ASPEED_JTAG_ISR_INT_MASK;
+       }
+
+       if (aspeed_jtag->flag) {
+               wake_up_interruptible(&aspeed_jtag->jtag_wq);
+               ret = IRQ_HANDLED;
+       } else {
+               dev_err(aspeed_jtag->dev, "aspeed_jtag irq status:%x\n",

using dev_err will give you sensible prefixes for any messages that
print out. You could remove "aspeed_jtag" from this any any other
prints you have.

+                       status);
+               ret = IRQ_NONE;
+       }
+       return ret;
+}
+
+int aspeed_jtag_init(struct platform_device *pdev,
+                    struct aspeed_jtag *aspeed_jtag)
+{
+       struct resource *res;
+       int err;
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       aspeed_jtag->reg_base = devm_ioremap_resource(aspeed_jtag->dev, res);
+       if (IS_ERR(aspeed_jtag->reg_base))
+               return -ENOMEM;
+
+       aspeed_jtag->pclk = devm_clk_get(aspeed_jtag->dev, NULL);
+       if (IS_ERR(aspeed_jtag->pclk)) {
+               dev_err(aspeed_jtag->dev, "devm_clk_get failed\n");
+               return PTR_ERR(aspeed_jtag->pclk);
+       }
+
+       clk_prepare_enable(aspeed_jtag->pclk);

Can you move this below the platform_get_irq? that way you can return
an error if the getting the IRQ fails, without having to clean up the
clock.

+
+       aspeed_jtag->irq = platform_get_irq(pdev, 0);
+       if (aspeed_jtag->irq < 0) {
+               dev_err(aspeed_jtag->dev, "no irq specified\n");
+               err = -ENOENT;
+               goto clk_unprep;
+       }
+
+       /* Enable clock */
+       aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_CTL_ENG_EN |
+                         ASPEED_JTAG_CTL_ENG_OUT_EN, ASPEED_JTAG_CTRL);
+       aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+                         ASPEED_JTAG_SW_MODE_TDIO, ASPEED_JTAG_SW);
+
+       err = devm_request_irq(aspeed_jtag->dev, aspeed_jtag->irq,
+                              aspeed_jtag_interrupt, 0,
+                              "aspeed-jtag", aspeed_jtag);
+       if (err) {
+               dev_err(aspeed_jtag->dev, "aspeed_jtag unable to get IRQ");
+               goto clk_unprep;
+       }
+       dev_dbg(&pdev->dev, "aspeed_jtag:IRQ %d.\n", aspeed_jtag->irq);

Again, remove the aspeed_jtag prefix.

+
+       aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_ISR_INST_PAUSE |
+                         ASPEED_JTAG_ISR_INST_COMPLETE |
+                         ASPEED_JTAG_ISR_DATA_PAUSE |
+                         ASPEED_JTAG_ISR_DATA_COMPLETE |
+                         ASPEED_JTAG_ISR_INST_PAUSE_EN |
+                         ASPEED_JTAG_ISR_INST_COMPLETE_EN |
+                         ASPEED_JTAG_ISR_DATA_PAUSE_EN |
+                         ASPEED_JTAG_ISR_DATA_COMPLETE_EN,
+                         ASPEED_JTAG_ISR);
+
+       aspeed_jtag->flag = 0;
+       aspeed_jtag->mode = 0;
+       init_waitqueue_head(&aspeed_jtag->jtag_wq);
+       return 0;
+
+clk_unprep:
+       clk_disable_unprepare(aspeed_jtag->pclk);
+       return err;
+}
+
+int aspeed_jtag_deinit(struct platform_device *pdev,
+                      struct aspeed_jtag *aspeed_jtag)
+{
+       aspeed_jtag_write(aspeed_jtag, 0, ASPEED_JTAG_ISR);
+       /* Disable clock */
+       aspeed_jtag_write(aspeed_jtag, 0, ASPEED_JTAG_CTRL);
+       clk_disable_unprepare(aspeed_jtag->pclk);
+       return 0;
+}
+
+static const struct jtag_ops aspeed_jtag_ops = {
+       .freq_get = aspeed_jtag_freq_get,
+       .freq_set = aspeed_jtag_freq_set,
+       .status_get = aspeed_jtag_status_get,
+       .idle = aspeed_jtag_idle,
+       .xfer = aspeed_jtag_xfer,
+       .mode_set = aspeed_jtag_mode_set
+};
+
+static int aspeed_jtag_probe(struct platform_device *pdev)
+{
+       struct aspeed_jtag *aspeed_jtag;
+       struct device *dev;
+       struct jtag *jtag;
+       int err;
+
+       dev = &pdev->dev;
+       if (!of_device_is_compatible(pdev->dev.of_node,
+                                    "aspeed,ast2500-jtag") &&
+           !of_device_is_compatible(pdev->dev.of_node,
+                                    "aspeed,ast2400-jtag"))
+               return -ENODEV;

Given the Aspeed device only ever probes with device tree,  can you
drop these redundant checks?

+
+       jtag = jtag_alloc(sizeof(*aspeed_jtag), &aspeed_jtag_ops);
+       if (!jtag)
+               return -ENOMEM;
+
+       platform_set_drvdata(pdev, jtag);
+       aspeed_jtag = jtag_priv(jtag);
+       aspeed_jtag->dev = &pdev->dev;
+
+       /* Initialize device*/
+       err = aspeed_jtag_init(pdev, aspeed_jtag);
+       if (err)
+               goto err_jtag_init;
+
+       /* Initialize JTAG core structure*/
+       err = jtag_register(jtag);
+       if (err)
+               goto err_jtag_register;
+
+       return 0;
+
+err_jtag_register:
+       aspeed_jtag_deinit(pdev, aspeed_jtag);
+err_jtag_init:
+       jtag_free(jtag);
+       return err;
+}
+
+static int aspeed_jtag_remove(struct platform_device *pdev)
+{
+       struct jtag *jtag;
+
+       jtag = platform_get_drvdata(pdev);
+       aspeed_jtag_deinit(pdev, jtag_priv(jtag));
+       jtag_unregister(jtag);
+       jtag_free(jtag);
+       return 0;
+}
+
+static const struct of_device_id aspeed_jtag_of_match[] = {
+       { .compatible = "aspeed,ast2400-jtag", },
+       { .compatible = "aspeed,ast2500-jtag", },
+       {}
+};
+
+static struct platform_driver aspeed_jtag_driver = {
+       .probe = aspeed_jtag_probe,
+       .remove = aspeed_jtag_remove,
+       .driver = {
+               .name = ASPEED_JTAG_NAME,
+               .of_match_table = aspeed_jtag_of_match,
+       },
+};
+module_platform_driver(aspeed_jtag_driver);
+
+MODULE_AUTHOR("Oleksandr Shamray [off-list ref]");
+MODULE_DESCRIPTION("ASPEED JTAG driver");
+MODULE_LICENSE("GPL v2");
--
1.7.1

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