Re: [patch v12 2/4] drivers: jtag: Add Aspeed SoC 24xx and 25xx families JTAG master driver

[Kun Yi]

Thanks for working on the driver, Oleksandr. I gave this a try on a
board with Aspeed 2520. One question below:

On Tue, Nov 14, 2017 at 8:11 AM, Oleksandr Shamray
<oleksandrs@xxxxxxxxxxxx> wrote:
> Driver adds support of Aspeed 2500/2400 series SOC JTAG master controller.
>
> Driver implements the following jtag ops:
> - freq_get;
> - freq_set;
> - status_get;
> - idle;
> - xfer;
>
> It has been tested on Mellanox system with BMC equipped with
> Aspeed 2520 SoC for programming CPLD devices.
>
> Signed-off-by: Oleksandr Shamray <oleksandrs@xxxxxxxxxxxx>
> Signed-off-by: Jiri Pirko <jiri@xxxxxxxxxxxx>
> Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
> v11->v12
> Comments pointed by Chip Bilbrey <chip@xxxxxxxxxxx>
> - Remove access mode from xfer and idle transactions
> - Add new ioctl JTAG_SIOCMODE for set hw mode
>
> v10->v11
> v9->v10
> V8->v9
> Comments pointed by Arnd Bergmann <arnd@xxxxxxxx>
> - add *data parameter to xfer function prototype
>
> v7->v8
> Comments pointed by Joel Stanley <joel.stan@xxxxxxxxx>
> - aspeed_jtag_init replace goto to return;
> - change input variables type from __u32 to u32
>   in functios freq_get, freq_set, status_get
> - change sm_ variables type from char to u8
> - in jatg_init add disable clocks on error case
> - remove release_mem_region on error case
> - remove devm_free_irq on jtag_deinit
> - Fix misspelling Disabe/Disable
> - Change compatible string to ast2400 and ast2000
>
> v6->v7
> Notifications from kbuild test robot <lkp@xxxxxxxxx>
> - Add include <linux/types.h> to jtag-asapeed.c
>
> v5->v6
> v4->v5
> Comments pointed by Arnd Bergmann <arnd@xxxxxxxx>
> - Added HAS_IOMEM dependence in Kconfig to avoid
>   "undefined reference to `devm_ioremap_resource'" error,
>   because in some arch this not supported
>
> v3->v4
> Comments pointed by Arnd Bergmann <arnd@xxxxxxxx>
> - change transaction pointer tdio type  to __u64
> - change internal status type from enum to __u32
>
> v2->v3
>
> v1->v2
> Comments pointed by Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>
> - change license type from GPLv2/BSD to GPLv2
>
> Comments pointed by Neil Armstrong <narmstrong@xxxxxxxxxxxx>
> - Add clk_prepare_enable/clk_disable_unprepare in clock init/deinit
> - Change .compatible to soc-specific compatible names
>   aspeed,aspeed4000-jtag/aspeed5000-jtag
> - Added dt-bindings
>
> Comments pointed by Arnd Bergmann <arnd@xxxxxxxx>
> - Reorder functions and removed the forward declarations
> - Add static const qualifier to state machine states transitions
> - Change .compatible to soc-specific compatible names
>   aspeed,aspeed4000-jtag/aspeed5000-jtag
> - Add dt-bindings
>
> Comments pointed by Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> - Change module name jtag-aspeed in description in Kconfig
>
> Comments pointed by kbuild test robot <lkp@xxxxxxxxx>
> - Remove invalid include <asm/mach-types.h>
> - add resource_size instead of calculation
> ---
>  drivers/jtag/Kconfig       |   13 +
>  drivers/jtag/Makefile      |    1 +
>  drivers/jtag/jtag-aspeed.c |  782 ++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 796 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/jtag/jtag-aspeed.c
>
> diff --git a/drivers/jtag/Kconfig b/drivers/jtag/Kconfig
> index 0fad1a3..098beb0 100644
> --- a/drivers/jtag/Kconfig
> +++ b/drivers/jtag/Kconfig
> @@ -14,3 +14,16 @@ menuconfig JTAG
>
>           To compile this driver as a module, choose M here: the module will
>           be called jtag.
> +
> +menuconfig JTAG_ASPEED
> +       tristate "Aspeed SoC JTAG controller support"
> +       depends on JTAG && HAS_IOMEM
> +       ---help---
> +         This provides a support for Aspeed JTAG device, equipped on
> +         Aspeed SoC 24xx and 25xx families. Drivers allows programming
> +         of hardware devices, connected to SoC through the JTAG interface.
> +
> +         If you want this support, you should say Y here.
> +
> +         To compile this driver as a module, choose M here: the module will
> +         be called jtag-aspeed.
> diff --git a/drivers/jtag/Makefile b/drivers/jtag/Makefile
> index af37493..04a855e 100644
> --- a/drivers/jtag/Makefile
> +++ b/drivers/jtag/Makefile
> @@ -1 +1,2 @@
>  obj-$(CONFIG_JTAG)             += jtag.o
> +obj-$(CONFIG_JTAG_ASPEED)      += jtag-aspeed.o
> diff --git a/drivers/jtag/jtag-aspeed.c b/drivers/jtag/jtag-aspeed.c
> new file mode 100644
> index 0000000..a6e2417
> --- /dev/null
> +++ b/drivers/jtag/jtag-aspeed.c
> @@ -0,0 +1,782 @@
> +/*
> + * drivers/jtag/aspeed-jtag.c
> + *
> + * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
> + * Copyright (c) 2017 Oleksandr Shamray <oleksandrs@xxxxxxxxxxxx>
> + *
> + * Released under the GPLv2 only.
> + * SPDX-License-Identifier: GPL-2.0
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/device.h>
> +#include <linux/interrupt.h>
> +#include <linux/jtag.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of_address.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +#include <linux/types.h>
> +#include <uapi/linux/jtag.h>
> +
> +#define ASPEED_JTAG_DATA               0x00
> +#define ASPEED_JTAG_INST               0x04
> +#define ASPEED_JTAG_CTRL               0x08
> +#define ASPEED_JTAG_ISR                        0x0C
> +#define ASPEED_JTAG_SW                 0x10
> +#define ASPEED_JTAG_TCK                        0x14
> +#define ASPEED_JTAG_EC                 0x18
> +
> +#define ASPEED_JTAG_DATA_MSB           0x01
> +#define ASPEED_JTAG_DATA_CHUNK_SIZE    0x20
> +
> +/* ASPEED_JTAG_CTRL: Engine Control */
> +#define ASPEED_JTAG_CTL_ENG_EN         BIT(31)
> +#define ASPEED_JTAG_CTL_ENG_OUT_EN     BIT(30)
> +#define ASPEED_JTAG_CTL_FORCE_TMS      BIT(29)
> +#define ASPEED_JTAG_CTL_INST_LEN(x)    ((x) << 20)
> +#define ASPEED_JTAG_CTL_LASPEED_INST   BIT(17)
> +#define ASPEED_JTAG_CTL_INST_EN                BIT(16)
> +#define ASPEED_JTAG_CTL_DR_UPDATE      BIT(10)
> +#define ASPEED_JTAG_CTL_DATA_LEN(x)    ((x) << 4)
> +#define ASPEED_JTAG_CTL_LASPEED_DATA   BIT(1)
> +#define ASPEED_JTAG_CTL_DATA_EN                BIT(0)
> +
> +/* ASPEED_JTAG_ISR : Interrupt status and enable */
> +#define ASPEED_JTAG_ISR_INST_PAUSE     BIT(19)
> +#define ASPEED_JTAG_ISR_INST_COMPLETE  BIT(18)
> +#define ASPEED_JTAG_ISR_DATA_PAUSE     BIT(17)
> +#define ASPEED_JTAG_ISR_DATA_COMPLETE  BIT(16)
> +#define ASPEED_JTAG_ISR_INST_PAUSE_EN  BIT(3)
> +#define ASPEED_JTAG_ISR_INST_COMPLETE_EN BIT(2)
> +#define ASPEED_JTAG_ISR_DATA_PAUSE_EN  BIT(1)
> +#define ASPEED_JTAG_ISR_DATA_COMPLETE_EN BIT(0)
> +#define ASPEED_JTAG_ISR_INT_EN_MASK    GENMASK(3, 0)
> +#define ASPEED_JTAG_ISR_INT_MASK       GENMASK(19, 16)
> +
> +/* ASPEED_JTAG_SW : Software Mode and Status */
> +#define ASPEED_JTAG_SW_MODE_EN         BIT(19)
> +#define ASPEED_JTAG_SW_MODE_TCK                BIT(18)
> +#define ASPEED_JTAG_SW_MODE_TMS                BIT(17)
> +#define ASPEED_JTAG_SW_MODE_TDIO       BIT(16)
> +
> +/* ASPEED_JTAG_TCK : TCK Control */
> +#define ASPEED_JTAG_TCK_DIVISOR_MASK   GENMASK(10, 0)
> +#define ASPEED_JTAG_TCK_GET_DIV(x)     ((x) & ASPEED_JTAG_TCK_DIVISOR_MASK)
> +
> +/* ASPEED_JTAG_EC : Controller set for go to IDLE */
> +#define ASPEED_JTAG_EC_GO_IDLE         BIT(0)
> +
> +#define ASPEED_JTAG_IOUT_LEN(len)      (ASPEED_JTAG_CTL_ENG_EN |\
> +                                        ASPEED_JTAG_CTL_ENG_OUT_EN |\
> +                                        ASPEED_JTAG_CTL_INST_LEN(len))
> +
> +#define ASPEED_JTAG_DOUT_LEN(len)      (ASPEED_JTAG_CTL_ENG_EN |\
> +                                        ASPEED_JTAG_CTL_ENG_OUT_EN |\
> +                                        ASPEED_JTAG_CTL_DATA_LEN(len))
> +
> +#define ASPEED_JTAG_TCK_WAIT           10
> +#define ASPEED_JTAG_RESET_CNTR         10
> +
> +#define ASPEED_JTAG_NAME               "jtag-aspeed"
> +
> +struct aspeed_jtag {
> +       void __iomem                    *reg_base;
> +       struct device                   *dev;
> +       struct clk                      *pclk;
> +       enum jtag_endstate              status;
> +       int                             irq;
> +       u32                             flag;
> +       wait_queue_head_t               jtag_wq;
> +       u32                             mode;
> +};
> +
> +static char *end_status_str[] = {"idle", "ir pause", "drpause"};
> +
> +static u32 aspeed_jtag_read(struct aspeed_jtag *aspeed_jtag, u32 reg)
> +{
> +       return readl(aspeed_jtag->reg_base + reg);
> +}
> +
> +static void
> +aspeed_jtag_write(struct aspeed_jtag *aspeed_jtag, u32 val, u32 reg)
> +{
> +       writel(val, aspeed_jtag->reg_base + reg);
> +}
> +
> +static int aspeed_jtag_freq_set(struct jtag *jtag, u32 freq)
> +{
> +       struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
> +       unsigned long apb_frq;
> +       u32 tck_val;
> +       u16 div;
> +
> +       apb_frq = clk_get_rate(aspeed_jtag->pclk);
> +       div = (apb_frq % freq == 0) ? (apb_frq / freq) - 1 : (apb_frq / freq);
> +       tck_val = aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_TCK);
> +       aspeed_jtag_write(aspeed_jtag,
> +                         (tck_val & ASPEED_JTAG_TCK_DIVISOR_MASK) | div,
> +                         ASPEED_JTAG_TCK);
> +       return 0;
> +}
> +
> +static int aspeed_jtag_freq_get(struct jtag *jtag, u32 *frq)
> +{
> +       struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
> +       u32 pclk;
> +       u32 tck;
> +
> +       pclk = clk_get_rate(aspeed_jtag->pclk);
> +       tck = aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_TCK);
> +       *frq = pclk / (ASPEED_JTAG_TCK_GET_DIV(tck) + 1);
> +
> +       return 0;
> +}
> +
> +static int aspeed_jtag_mode_set(struct jtag *jtag, u32 mode)
> +{
> +       struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
> +
> +       aspeed_jtag->mode = mode;
> +       return 0;
> +}
> +
> +static void aspeed_jtag_sw_delay(struct aspeed_jtag *aspeed_jtag, int cnt)
> +{
> +       int i;
> +
> +       for (i = 0; i < cnt; i++)
> +               aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_SW);
> +}
> +
> +static char aspeed_jtag_tck_cycle(struct aspeed_jtag *aspeed_jtag,
> +                                 u8 tms, u8 tdi)
> +{
> +       char tdo = 0;
> +
> +       /* TCK = 0 */
> +       aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
> +                         (tms * ASPEED_JTAG_SW_MODE_TMS) |
> +                         (tdi * ASPEED_JTAG_SW_MODE_TDIO), ASPEED_JTAG_SW);
> +
> +       aspeed_jtag_sw_delay(aspeed_jtag, ASPEED_JTAG_TCK_WAIT);
> +
> +       /* TCK = 1 */
> +       aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
> +                         ASPEED_JTAG_SW_MODE_TCK |
> +                         (tms * ASPEED_JTAG_SW_MODE_TMS) |
> +                         (tdi * ASPEED_JTAG_SW_MODE_TDIO), ASPEED_JTAG_SW);
> +
> +       if (aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_SW) &
> +           ASPEED_JTAG_SW_MODE_TDIO)
> +               tdo = 1;
> +
> +       aspeed_jtag_sw_delay(aspeed_jtag, ASPEED_JTAG_TCK_WAIT);
> +
> +       /* TCK = 0 */
> +       aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
> +                         (tms * ASPEED_JTAG_SW_MODE_TMS) |
> +                         (tdi * ASPEED_JTAG_SW_MODE_TDIO), ASPEED_JTAG_SW);
> +       return tdo;
> +}
> +
> +static void aspeed_jtag_wait_instruction_pause(struct aspeed_jtag *aspeed_jtag)
> +{
> +       wait_event_interruptible(aspeed_jtag->jtag_wq, aspeed_jtag->flag &
> +                                ASPEED_JTAG_ISR_INST_PAUSE);
> +       aspeed_jtag->flag &= ~ASPEED_JTAG_ISR_INST_PAUSE;
> +}
> +
> +static void
> +aspeed_jtag_wait_instruction_complete(struct aspeed_jtag *aspeed_jtag)
> +{
> +       wait_event_interruptible(aspeed_jtag->jtag_wq, aspeed_jtag->flag &
> +                                ASPEED_JTAG_ISR_INST_COMPLETE);
> +       aspeed_jtag->flag &= ~ASPEED_JTAG_ISR_INST_COMPLETE;
> +}
> +
> +static void
> +aspeed_jtag_wait_data_pause_complete(struct aspeed_jtag *aspeed_jtag)
> +{
> +       wait_event_interruptible(aspeed_jtag->jtag_wq, aspeed_jtag->flag &
> +                                ASPEED_JTAG_ISR_DATA_PAUSE);
> +       aspeed_jtag->flag &= ~ASPEED_JTAG_ISR_DATA_PAUSE;
> +}
> +
> +static void aspeed_jtag_wait_data_complete(struct aspeed_jtag *aspeed_jtag)
> +{
> +       wait_event_interruptible(aspeed_jtag->jtag_wq, aspeed_jtag->flag &
> +                                ASPEED_JTAG_ISR_DATA_COMPLETE);
> +       aspeed_jtag->flag &= ~ASPEED_JTAG_ISR_DATA_COMPLETE;
> +}
> +
> +static void aspeed_jtag_sm_cycle(struct aspeed_jtag *aspeed_jtag, const u8 *tms,
> +                                int len)
> +{
> +       int i;
> +
> +       for (i = 0; i < len; i++)
> +               aspeed_jtag_tck_cycle(aspeed_jtag, tms[i], 0);
> +}
> +
> +static void aspeed_jtag_run_test_idle_sw(struct aspeed_jtag *aspeed_jtag,
> +                                        struct jtag_run_test_idle *runtest)
> +{
> +       static const u8 sm_pause_irpause[] = {1, 1, 1, 1, 0, 1, 0};
> +       static const u8 sm_pause_drpause[] = {1, 1, 1, 0, 1, 0};
> +       static const u8 sm_idle_irpause[] = {1, 1, 0, 1, 0};
> +       static const u8 sm_idle_drpause[] = {1, 0, 1, 0};
> +       static const u8 sm_pause_idle[] = {1, 1, 0};
> +       int i;
> +
> +       /* SW mode from idle/pause-> to pause/idle */
> +       if (runtest->reset) {
> +               for (i = 0; i < ASPEED_JTAG_RESET_CNTR; i++)
> +                       aspeed_jtag_tck_cycle(aspeed_jtag, 1, 0);
> +       }
> +
> +       switch (aspeed_jtag->status) {
> +       case JTAG_STATE_IDLE:
> +               switch (runtest->endstate) {
> +               case JTAG_STATE_PAUSEIR:
> +                       /* ->DRSCan->IRSCan->IRCap->IRExit1->PauseIR */
> +                       aspeed_jtag_sm_cycle(aspeed_jtag, sm_idle_irpause,
> +                                            sizeof(sm_idle_irpause));
> +
> +                       aspeed_jtag->status = JTAG_STATE_PAUSEIR;
> +                       break;
> +               case JTAG_STATE_PAUSEDR:
> +                       /* ->DRSCan->DRCap->DRExit1->PauseDR */
> +                       aspeed_jtag_sm_cycle(aspeed_jtag, sm_idle_drpause,
> +                                            sizeof(sm_idle_drpause));
> +
> +                       aspeed_jtag->status = JTAG_STATE_PAUSEDR;
> +                       break;
> +               case JTAG_STATE_IDLE:
> +                       /* IDLE */
> +                       aspeed_jtag_tck_cycle(aspeed_jtag, 0, 0);
> +                       aspeed_jtag->status = JTAG_STATE_IDLE;
> +                       break;
> +               default:
> +                       break;
> +               }
> +               break;
> +
> +       case JTAG_STATE_PAUSEIR:
> +       /* Fall-through */
> +       case JTAG_STATE_PAUSEDR:
> +               /* From IR/DR Pause */
> +               switch (runtest->endstate) {
> +               case JTAG_STATE_PAUSEIR:
> +                       /*
> +                        * to Exit2 IR/DR->Updt IR/DR->DRSCan->IRSCan->IRCap->
> +                        * IRExit1->PauseIR
> +                        */
> +                       aspeed_jtag_sm_cycle(aspeed_jtag, sm_pause_irpause,
> +                                            sizeof(sm_pause_irpause));
> +
> +                       aspeed_jtag->status = JTAG_STATE_PAUSEIR;
> +                       break;
> +               case JTAG_STATE_PAUSEDR:
> +                       /*
> +                        * to Exit2 IR/DR->Updt IR/DR->DRSCan->DRCap->
> +                        * DRExit1->PauseDR
> +                        */
> +                       aspeed_jtag_sm_cycle(aspeed_jtag, sm_pause_drpause,
> +                                            sizeof(sm_pause_drpause));
> +                       aspeed_jtag->status = JTAG_STATE_PAUSEDR;
> +                       break;
> +               case JTAG_STATE_IDLE:
> +                       /* to Exit2 IR/DR->Updt IR/DR->IDLE */
> +                       aspeed_jtag_sm_cycle(aspeed_jtag, sm_pause_idle,
> +                                            sizeof(sm_pause_idle));
> +                       aspeed_jtag->status = JTAG_STATE_IDLE;
> +                       break;
> +               default:
> +                       break;
> +               }
> +               break;
> +
> +       default:
> +               dev_err(aspeed_jtag->dev, "aspeed_jtag_run_test_idle error\n");
> +               break;
> +       }
> +
> +       /* Stay on IDLE for at least  TCK cycle */
> +       for (i = 0; i < runtest->tck; i++)
> +               aspeed_jtag_tck_cycle(aspeed_jtag, 0, 0);
> +}
> +
> +/**
> + * aspeed_jtag_run_test_idle:
> + * JTAG reset: generates at least 9 TMS high and 1 TMS low to force
> + * devices into Run-Test/Idle State.
> + */
> +static int aspeed_jtag_idle(struct jtag *jtag,
> +                           struct jtag_run_test_idle *runtest)
> +{
> +       struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
> +
> +       dev_dbg(aspeed_jtag->dev, "aspeed_jtag runtest, status:%d, mode:%s, state:%s, reset:%d, tck:%d\n",
> +               aspeed_jtag->status,
> +               aspeed_jtag->mode & JTAG_XFER_HW_MODE ? "HW" : "SW",
> +               end_status_str[runtest->endstate], runtest->reset,
> +               runtest->tck);
> +
> +       if (!(aspeed_jtag->mode & JTAG_XFER_HW_MODE)) {
> +               aspeed_jtag_run_test_idle_sw(aspeed_jtag, runtest);
> +               return 0;
> +       }
> +
> +       /* Disable sw mode */
> +       aspeed_jtag_write(aspeed_jtag, 0, ASPEED_JTAG_SW);
> +       /* x TMS high + 1 TMS low */
> +       if (runtest->reset)
> +               aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_CTL_ENG_EN |
> +                                 ASPEED_JTAG_CTL_ENG_OUT_EN |
> +                                 ASPEED_JTAG_CTL_FORCE_TMS, ASPEED_JTAG_CTRL);
> +       else
> +               aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_EC_GO_IDLE,
> +                                 ASPEED_JTAG_EC);
> +
> +       aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
> +                         ASPEED_JTAG_SW_MODE_TDIO, ASPEED_JTAG_SW);
> +
> +       aspeed_jtag->status = JTAG_STATE_IDLE;
> +       return 0;
> +}
> +
> +static void aspeed_jtag_xfer_sw(struct aspeed_jtag *aspeed_jtag,
> +                               struct jtag_xfer *xfer, unsigned long *data)
> +{
> +       unsigned long remain_xfer = xfer->length;
> +       unsigned long shift_bits = 0;
> +       unsigned long index = 0;
> +       unsigned long tdi;
> +       char          tdo;
> +
> +       if (xfer->direction == JTAG_READ_XFER)
> +               tdi = UINT_MAX;
> +       else
> +               tdi = data[index];
> +
> +       while (remain_xfer > 1) {
> +               tdo = aspeed_jtag_tck_cycle(aspeed_jtag, 0,
> +                                           tdi & ASPEED_JTAG_DATA_MSB);
> +               data[index] |= tdo << (shift_bits %
> +                                           ASPEED_JTAG_DATA_CHUNK_SIZE);
> +
> +               tdi >>= 1;
> +               shift_bits++;
> +               remain_xfer--;
> +
> +               if (shift_bits % ASPEED_JTAG_DATA_CHUNK_SIZE == 0) {
> +                       dev_dbg(aspeed_jtag->dev, "R/W data[%lu]:%lx\n",
> +                               index, data[index]);
> +
> +                       tdo = 0;
> +                       index++;
> +
> +                       if (xfer->direction == JTAG_READ_XFER)
> +                               tdi = UINT_MAX;
> +                       else
> +                               tdi = data[index];
> +               }
> +       }
> +
> +       tdo = aspeed_jtag_tck_cycle(aspeed_jtag, 1, tdi & ASPEED_JTAG_DATA_MSB);
> +       data[index] |= tdo << (shift_bits % ASPEED_JTAG_DATA_CHUNK_SIZE);
> +}
> +
> +static void aspeed_jtag_xfer_push_data(struct aspeed_jtag *aspeed_jtag,
> +                                      enum jtag_xfer_type type, u32 bits_len)
> +{
> +       dev_dbg(aspeed_jtag->dev, "shift bits %d\n", bits_len);
> +
> +       if (type == JTAG_SIR_XFER) {
> +               aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_IOUT_LEN(bits_len),
> +                                 ASPEED_JTAG_CTRL);
> +               aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_DOUT_LEN(bits_len) |
> +                                 ASPEED_JTAG_CTL_INST_EN, ASPEED_JTAG_CTRL);
> +       } else {
> +               aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_DOUT_LEN(bits_len),
> +                                 ASPEED_JTAG_CTRL);
> +               aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_DOUT_LEN(bits_len) |
> +                                 ASPEED_JTAG_CTL_DATA_EN, ASPEED_JTAG_CTRL);
> +       }
> +}
> +
> +static void aspeed_jtag_xfer_push_data_last(struct aspeed_jtag *aspeed_jtag,
> +                                           enum jtag_xfer_type type,
> +                                           u32 shift_bits,
> +                                           enum jtag_endstate endstate)
> +{
> +       if (endstate != JTAG_STATE_IDLE) {
> +               if (type == JTAG_SIR_XFER) {
> +                       dev_dbg(aspeed_jtag->dev, "IR Keep Pause\n");
> +
> +                       aspeed_jtag_write(aspeed_jtag,
> +                                         ASPEED_JTAG_IOUT_LEN(shift_bits),
> +                                         ASPEED_JTAG_CTRL);
> +                       aspeed_jtag_write(aspeed_jtag,
> +                                         ASPEED_JTAG_IOUT_LEN(shift_bits) |
> +                                         ASPEED_JTAG_CTL_INST_EN,
> +                                         ASPEED_JTAG_CTRL);
> +                       aspeed_jtag_wait_instruction_pause(aspeed_jtag);
> +               } else {
> +                       dev_dbg(aspeed_jtag->dev, "DR Keep Pause\n");
> +                       aspeed_jtag_write(aspeed_jtag,
> +                                         ASPEED_JTAG_DOUT_LEN(shift_bits) |
> +                                         ASPEED_JTAG_CTL_DR_UPDATE,
> +                                         ASPEED_JTAG_CTRL);
> +                       aspeed_jtag_write(aspeed_jtag,
> +                                         ASPEED_JTAG_DOUT_LEN(shift_bits) |
> +                                         ASPEED_JTAG_CTL_DR_UPDATE |
> +                                         ASPEED_JTAG_CTL_DATA_EN,
> +                                         ASPEED_JTAG_CTRL);
> +                       aspeed_jtag_wait_data_pause_complete(aspeed_jtag);
> +               }
> +       } else {
> +               if (type == JTAG_SIR_XFER) {
> +                       dev_dbg(aspeed_jtag->dev, "IR go IDLE\n");
> +
> +                       aspeed_jtag_write(aspeed_jtag,
> +                                         ASPEED_JTAG_IOUT_LEN(shift_bits) |
> +                                         ASPEED_JTAG_CTL_LASPEED_INST,
> +                                         ASPEED_JTAG_CTRL);
> +                       aspeed_jtag_write(aspeed_jtag,
> +                                         ASPEED_JTAG_IOUT_LEN(shift_bits) |
> +                                         ASPEED_JTAG_CTL_LASPEED_INST |
> +                                         ASPEED_JTAG_CTL_INST_EN,
> +                                         ASPEED_JTAG_CTRL);
> +                       aspeed_jtag_wait_instruction_complete(aspeed_jtag);
> +               } else {
> +                       dev_dbg(aspeed_jtag->dev, "DR go IDLE\n");
> +
> +                       aspeed_jtag_write(aspeed_jtag,
> +                                         ASPEED_JTAG_DOUT_LEN(shift_bits) |
> +                                         ASPEED_JTAG_CTL_LASPEED_DATA,
> +                                         ASPEED_JTAG_CTRL);
> +                       aspeed_jtag_write(aspeed_jtag,
> +                                         ASPEED_JTAG_DOUT_LEN(shift_bits) |
> +                                         ASPEED_JTAG_CTL_LASPEED_DATA |
> +                                         ASPEED_JTAG_CTL_DATA_EN,
> +                                         ASPEED_JTAG_CTRL);
> +                       aspeed_jtag_wait_data_complete(aspeed_jtag);
> +               }
> +       }
> +}
> +
> +static void aspeed_jtag_xfer_hw(struct aspeed_jtag *aspeed_jtag,
> +                               struct jtag_xfer *xfer, unsigned long *data)
> +{
> +       unsigned long remain_xfer = xfer->length;
> +       unsigned long index = 0;
> +       char shift_bits;
> +       u32 data_reg;
> +
> +       data_reg = xfer->type == JTAG_SIR_XFER ?
> +                  ASPEED_JTAG_INST : ASPEED_JTAG_DATA;
> +       while (remain_xfer) {
> +               if (xfer->direction == JTAG_WRITE_XFER) {
> +                       dev_dbg(aspeed_jtag->dev, "W dr->dr_data[%lu]:%lx\n",
> +                               index, data[index]);
> +
> +                       aspeed_jtag_write(aspeed_jtag, data[index], data_reg);
> +               } else {
> +                       aspeed_jtag_write(aspeed_jtag, 0, data_reg);
> +               }
> +
> +               if (remain_xfer > ASPEED_JTAG_DATA_CHUNK_SIZE) {
> +                       shift_bits = ASPEED_JTAG_DATA_CHUNK_SIZE;
> +
> +                       /*
> +                        * Read bytes were not equals to column length
> +                        * and go to Pause-DR
> +                        */
> +                       aspeed_jtag_xfer_push_data(aspeed_jtag, xfer->type,
> +                                                  shift_bits);
> +               } else {
> +                       /*
> +                        * Read bytes equals to column length =>
> +                        * Update-DR
> +                        */
> +                       shift_bits = remain_xfer;
> +                       aspeed_jtag_xfer_push_data_last(aspeed_jtag, xfer->type,
> +                                                       shift_bits,
> +                                                       xfer->endstate);
> +               }
> +
> +               if (xfer->direction == JTAG_READ_XFER) {
> +                       if (shift_bits < ASPEED_JTAG_DATA_CHUNK_SIZE) {
> +                               data[index] = aspeed_jtag_read(aspeed_jtag,
> +                                                              data_reg);
> +
> +                               data[index] >>= ASPEED_JTAG_DATA_CHUNK_SIZE -
> +                                                               shift_bits;
> +                       } else {
> +                               data[index] = aspeed_jtag_read(aspeed_jtag,
> +                                                              data_reg);
> +                       }
> +                       dev_dbg(aspeed_jtag->dev, "R dr->dr_data[%lu]:%lx\n",
> +                               index, data[index]);
> +               }
> +
> +               remain_xfer = remain_xfer - shift_bits;
> +               index++;
> +               dev_dbg(aspeed_jtag->dev, "remain_xfer %lu\n", remain_xfer);
> +       }
> +}
> +
> +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++) {
> +               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 int aspeed_jtag_status_get(struct jtag *jtag, u32 *status)
> +{
> +       struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
> +
> +       *status = aspeed_jtag->status;
> +       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",
> +                       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);
> +
> +       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);
> +
> +       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 jtag *jtag;
> +       int err;
> +
> +       if (!of_device_is_compatible(pdev->dev.of_node, "aspeed,aspeed-jtag"))

Should this be "aspeed,ast2400-jtag"/"aspeed,ast2500-jtag" as
specified in the compatible string below?

> +               return -ENOMEM;
> +
> +       jtag = jtag_alloc(sizeof(*aspeed_jtag), &aspeed_jtag_ops);
> +       if (!jtag)
> +               return -ENODEV;
> +
> +       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 <oleksandrs@xxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("ASPEED JTAG driver");
> +MODULE_LICENSE("GPL v2");
> --
> 1.7.1
>



-- 
Regards,
Kun