@@ -53,6 +53,8 @@ struct sh_msiof_spi_priv {
void *rx_dma_page;
dma_addr_t tx_dma_addr;
dma_addr_t rx_dma_addr;
+ struct notifier_block clk_rate_change_nb;
+ u32 dev_max_speed_hz;
};
#define TMDR1 0x00 /* Transmit Mode Register 1 */
@@ -180,6 +182,10 @@ struct sh_msiof_spi_priv {
#define IER_RFOVFE 0x00000008 /* Receive FIFO Overflow Enable */
+/* Maximum internal divider */
+#define MAX_DIV 1024
+
+
static u32 sh_msiof_read(struct sh_msiof_spi_priv *p, int reg_offs)
{
switch (reg_offs) {
@@ -253,7 +259,7 @@ static struct {
static void sh_msiof_spi_set_clk_regs(struct sh_msiof_spi_priv *p,
unsigned long parent_rate, u32 spi_hz)
{
- unsigned long div = 1024;
+ unsigned long div = MAX_DIV;
u32 brps, scr;
size_t k;
@@ -526,6 +532,53 @@ static void sh_msiof_spi_read_fifo_s32u(struct sh_msiof_spi_priv *p,
put_unaligned(swab32(sh_msiof_read(p, RFDR) >> fs), &buf_32[k]);
}
+static int sh_msiof_clk_notifier_cb(struct notifier_block *nb,
+ unsigned long event, void *data)
+{
+ struct clk_notifier_data *ndata = data;
+ struct sh_msiof_spi_priv *p =
+ container_of(nb, struct sh_msiof_spi_priv, clk_rate_change_nb);
+
+ // FIXME locking
+
+ if (!p->dev_max_speed_hz)
+ return NOTIFY_OK;
+
+ switch (event) {
+ case PRE_RATE_CHANGE:
+ dev_info(&p->pdev->dev, "%s: %pC old_rate %lu new_rate %lu\n",
+ "PRE_RATE_CHANGE", ndata->clk, ndata->old_rate,
+ ndata->new_rate);
+ if (p->dev_max_speed_hz < ndata->new_rate / MAX_DIV) {
+ dev_err(&p->pdev->dev,
+ "New parent clock rate too high for %u\n",
+ p->dev_max_speed_hz);
+ return NOTIFY_STOP;
+ }
+ if (p->dev_max_speed_hz > ndata->new_rate) {
+ dev_warn(&p->pdev->dev,
+ "New parent clock rate too low for %u, ignoring\n",
+ p->dev_max_speed_hz);
+ }
+ return NOTIFY_OK;
+
+ case POST_RATE_CHANGE:
+ dev_info(&p->pdev->dev, "%s: %pC old_rate %lu new_rate %lu\n",
+ "POST_RATE_CHANGE", ndata->clk, ndata->old_rate,
+ ndata->new_rate);
+ return NOTIFY_OK;
+
+ case ABORT_RATE_CHANGE:
+ return NOTIFY_OK;
+
+ default:
+ dev_info(&p->pdev->dev,
+ "0x%lx: %pC old_rate %lu new_rate %lu\n", event,
+ ndata->clk, ndata->old_rate, ndata->new_rate);
+ return NOTIFY_DONE;
+ }
+}
+
static int sh_msiof_spi_setup(struct spi_device *spi)
{
struct device_node *np = spi->master->dev.of_node;
@@ -535,12 +588,14 @@ static int sh_msiof_spi_setup(struct spi_device *spi)
rate = clk_get_rate(p->clk);
max_speed_hz = rate;
- min_speed_hz = rate / 1024;
+ min_speed_hz = rate / MAX_DIV;
dev_info(&p->pdev->dev,
"%s: master speed min %u max %u, device speed max = %u\n",
__func__, min_speed_hz, max_speed_hz, spi->max_speed_hz);
+ p->dev_max_speed_hz = spi->max_speed_hz;
+
pm_runtime_get_sync(&p->pdev->dev);
if (!np) {
@@ -1263,6 +1318,10 @@ static int sh_msiof_spi_probe(struct platform_device *pdev)
p->pdev = pdev;
pm_runtime_enable(&pdev->dev);
+ p->clk_rate_change_nb.notifier_call = sh_msiof_clk_notifier_cb;
+ if (clk_notifier_register(p->clk, &p->clk_rate_change_nb))
+ dev_warn(&pdev->dev, "Unable to register clock notifier.\n");
+
/* Platform data may override FIFO sizes */
p->tx_fifo_size = chipdata->tx_fifo_size;
p->rx_fifo_size = chipdata->rx_fifo_size;
@@ -1299,6 +1358,7 @@ static int sh_msiof_spi_probe(struct platform_device *pdev)
return 0;
err2:
+ clk_notifier_unregister(p->clk, &p->clk_rate_change_nb);
sh_msiof_release_dma(p);
pm_runtime_disable(&pdev->dev);
err1:
@@ -1310,6 +1370,7 @@ static int sh_msiof_spi_remove(struct platform_device *pdev)
{
struct sh_msiof_spi_priv *p = platform_get_drvdata(pdev);
+ clk_notifier_unregister(p->clk, &p->clk_rate_change_nb);
sh_msiof_release_dma(p);
pm_runtime_disable(&pdev->dev);
return 0;